MACE (MALONE ANTEGRADE CONTINENCE ENEMA)
DESCRIPTION The Malone antegrade continence enema (MACE) procedure is performed mostly in children with complex constipation or fecal incontinence secondary to neurogenic dysfunction. Using the appendix, a continent catheterizable colonic stoma is made. Antegrade enemas delivered by this route produce complete colonic emptying and minimize fecal soiling.
REFERENCE
Hoy NY, Metcalfe P, Kiddoo DA, et al. Outcomes following fecal continence procedures in patients with neurogenic bowel dysfunction. J Urol. 2013;189(6):2293–2297.
MACRO-ORCHIDISM (MO)
DESCRIPTION Macro-orchidism (MO) is an increase of testicular volume, up to 25 mL, seen in the adult male. It is frequently associated with mental retardation with fragile X-chromosome. MO has also been described in association with bilateral testicular tumors, idiopathic precocious puberty, juvenile hypothyroidism, and, more rarely, with congenital testicular cysts (cystic testicular dysplasia). Management of MO must be conservative in all cases, and testicular biopsy must only be performed to diagnose leukemic infiltration, carcinoma in situ, or as part of a fertility workup. MO may be related pathogenically to some hormonal regulation mechanism or to higher seminiferous tubule sensitivity to FSH.
REFERENCE
Martinez-Garcia F, Regadera Gonzalez J, Cobo Nuñez P, et al. Macro-orchidism: New pathogenetic and histopathologic aspects. Espanol Urol. 1994;47(1):59–65.
MAG 3 RENAL SCAN
DESCRIPTION A nuclear medicine study is used to evaluate renal function and the presence of obstruction. MAG3 (technetium99m-mercaptoacetyltriglycine) is a nuclear isotope secreted by the renal tubules. Multiple images are taken over time to give anatomic details, including scarring and function of the kidney. A split differential function between the 2 kidneys is obtained. Commonly, furosemide is administered to induce diuresis, and the time for the kidney to clear 1/2 of the tracer is calculated (t1/2). A t1/2 of 0–10 min indicates nonobstructive drainage, 10–20 min is indeterminate, and >20 min is consistent with obstruction.
REFERENCE
Hubert KC, Palmer JS. Current diagnosis and management of fet al genitourinary abnormalities. Urol Clin North Am. 2007;34(1):89–101.
MAGPI HYPOSPADIAS REPAIR
DESCRIPTION The meatal advancement and glanuloplasty procedure (MAGPI) was 1st described by Duckett in 1981. After a circumferential subcoronal incision, the bridge of tissue immediately distal and dorsal to the meatus is split in a vertical fashion and closed in a horizontal orientation (Heineke–Mikulicz closure). The ventral edge of the new meatal opening is pulled up, and the glans is reapproximated ventrally, which, in effect, advances the meatus.
REFERENCE
Duckett JW. MAGPI (meatoplasty and glanuloplasty) a procedure for subcoronal hypospadias. 1981. J Urol. 2002;167(5):2153–2158.
MAINZ I, II, III POUCH URINARY DIVERSION
DESCRIPTION The Mainz I (ileocecal pouch) is an orthotopic pouch created by opening the cecum and 2 limbs of distal ileum; the limbs are then sutured to create a broad intestinal plate. After a tunneled ureterocolonic anastomosis is made, the cecal portion of the plate is anastomosed to the male urethral stump and the plate is closed into a sphere. The Mainz II (sigma rectum pouch) is an augmented valved rectum created by making a 10–12-cm rectosigmoid opening. The sigmoid colon is configured into a U shape, and the medial plate is closed. Ureters are implanted through submucosal tunnels. After securing the apex of the pouch to the sacral promontory, the remaining plate is closed. The Mainz III is a continent cutaneous pouch made exclusively of colon (transverse-ascending colon pouch or transverse-descending colon pouch) with the efferent segment created from a tapered bowel segment embedded in the pouch wall.
REFERENCE
Bader P, Westermann D, Frohneberg D. Urinary diversions: Which one is right for which patient? Urologe A. 2009;48(2):127–136.
MALACOPLAKIA, GENITOURINARY
DESCRIPTION Malacoplakia, derived from the Greek term for soft plaque, is a chronic inflammatory disease, the etiology of which remains obscure. It appears related to an underlying infectious process. It has a very low incidence and affects primarily the GU tract. The diagnosis is made by biopsy. The pathologic specimens typical of malacoplakia consist of large histiocytes known as von Hansemann cells and intracytoplasmic inclusions known as Michaelis–Gutmann bodies. The goal of treatment is to stabilize the disease process by controlling UTI (Image 
).
REFERENCES
Guner G, Akdogan B, Baydar DE. Malakoplakia of prostate as a complication of transrectal needle biopsy. Can J Urol. 2012;19(1):6124–6127.
Long JP Jr., Althausen AF. Malacoplakia: A 25-year experience with a review of the literature. J Urol. 1989;141(6):1328–1331.
MALARIA (BLACK WATER FEVER), UROLOGIC CONSIDERATIONS
DESCRIPTION The protozoan Plasmodium falciparum is the parasite responsible for malaria. From a urologic perspective, malaria can cause hemoglobinuria. Treatment includes full dose antimalarials with supportive care. Acute renal tubular necrosis can occur if the infection is left untreated and some patients with chronic malaria develop nephrotic syndrome. (See Section II: “Black-Water Fever.”)
REFERENCE
Kehinde EO, Anim JT, Hira PR. Parasites of urological importance. Urol Int. 2008;81:1–13.
MALE SEXUAL FUNCTION SCALE
DESCRIPTION An 8-question sexual health inventory completed by the patient, which assesses core components of male sexual function including desire, erection, ejaculation, and satisfaction. The scale is meant to screen for sexual health in both the primary care and urologic practice settings.
REFERENCE
Lue TF, Broderick GA. Evaluation and nonsurgical management of erectile dysfunction and premature ejaculation. In: Wein AJ, et al., eds. Campbell-Walsh Urology. 9th ed. Philadelphia, PA: Saunders Elsevier; 2007.
MALE SEXUAL HEALTH QUESTIONNAIRE (MSHQ) AND THE MSHQ SHORT FORM
DESCRIPTION A patient self-administered test developed in 2004, the MSHQ is a 25-question questionnaire that evaluates sexual function and satisfaction in older men with LUTS. It provides more in-depth assessment of ejaculatory function than previous measures of sexual dysfunction, mainly the International Index of Erectile Function (IIEF). A 4-item version is called the MSHQ short form, and both forms can be used in research settings as well as in clinical practice to assess ejaculatory dysfunction. (See Section VII: “Reference Tables: Male sexual health questionnaire, Short Form".)
REFERENCE
Rosen RC, Catania JA, Althof SE, et al. Development and validation of four-item version of Male Sexual Health Questionnaire to assess ejaculatory dysfunction. Urology. 2007;69(5):805–809.
MALROTATED KIDNEY/RENAL MALROTATION
DESCRIPTION Malrotated kidney occurs when the kidney does not rotate 90° medially during fet al development. As a result, the renal pelvis, which normally lies medial to the parenchyma, is located anterior to the parenchyma. Often a malrotated kidney is an incidental finding. Malrotation makes the kidney more susceptible to trauma, and is also commonly observed in ectopic kidneys. (See also Seection I: “Renal Ectopia.”) (Image )
REFERENCE
Graham SD, Glenn JF, Keane TE. Glenn’s Urologic Surgery. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008.
MARSHALL–MARCHETTI–KRANTZ (MMK) CYSTOURETHROPEXY
DESCRIPTION A historical procedure for the treatment of stress incontinence in women performed through a Pfannenstiel incision. The retropubic space is exposed and the urethra, vaginal wall, bladder neck, and bladder are identified. The original description reports placement of interrupted sutures to attach the paraurethral tissue to the back of the symphysis pubis, with the most proximal suture being at the bladder neck.
REFERENCE
Parnell JP 2nd, Marshall VF, Vaughan ED Jr. Primary management of urinary stress incontinence by the Marshall-Marchetti-Krantz vesicourethropexy. J Urol. 1982;127(4):679–682.
MARTIUS GRAFT
DESCRIPTION A surgical technique used to repair urinary-vaginal fistulae. The flap is a well-vascularized fat pad from the labia majora and receives its blood supply from the branches of the pudendal artery. It is tunneled beneath the labia minora into the vaginal lumen, where it is used an interposition graft at the site of the fistula repair. It serves as a well-vascularized barrier between suture layers to prevent recurrent fistula formation.
SYNONYMS
• Martius labial pedicle graft
• Martius labial fat pad
• Martius flap
REFERENCE
Rangnekar NP, Imdad Ali N, Kaul SA, et al. Role of the Martius procedure in the management of urinary-vaginal fistulas. J Am Coll Surg. 2003;191(3):259–263.
MATHIEU HYPOSPADIAS REPAIR
DESCRIPTION A ventral flap is mobilized based on the dartos blood supply, and it is transposed over the urethral plate to advance the meatus. The lateral wings of the glans are reapproximated over the repair.
REFERENCE
Minevich E, Pecha BR, Wacksman J, et al. Mathieu hypospadias repair: Experience in 202 patients. J Urol. 1999;162(6):2141–2142.
MATURATION ARREST
DESCRIPTION The term maturation arrest has been used to describe testicular biopsies in cases of infertility. 2 forms of maturation arrest have been described: Spermatogenic arrest and spermatocytic (meiotic) arrest. The arrest is most frequently observed at the primary spermatocyte level. Reversible arrest at that level can be due to heat, infections, and hormonal and nutritional factors. Irreversible arrest at the primary spermatocyte or spermatid level has a genetic origin due to chromosomal anomalies. The dysfunction occurs in somatic and germ cells.
REFERENCE
Martin-du Pan RC, Campana A. Physiopathology of spermatogenic arrest. Fertil Steril. 1993;60(6):937–946.
MAXIMUM ANDROGEN BLOCKADE (MAB)/COMBINED HORMONAL THERAPY (CHT)
DESCRIPTION The main concept behind maximum androgen blockade (MAB), sometimes referred to as combined hormonal therapy (CHT) or total androgen blockade is that by adding an antiandrogen in conjunction with surgical castration or LHRH agonist therapy, urologists can minimize the effects of any extragonadal sources of androgen production in patients with prostate cancer. This source was traditionally noted to be the adrenal gland. Studies have been conflicting with some showing prolonged survival in patients treated with MAB with advanced prostate cancer and others demonstrating no significant difference. In a large meta-analysis published by the Prostate Cancer Trialists’ Collaborative group, a nonsignificant 1.8% 5-yr survival was found in the MAB group. This study included 27 randomized trials and over 8,200 patients.
Short-term MAB (1–2 wk) is generally agreed to in men with newly diagnosed metastatic disease when starting androgen deprivation with an LHRH analog to block the so-called “flare” reaction. Most RTOG trials that combine radiation therapy and external beam radiation therapy for intermediate and high-risk disease are performed using MAB (6 mo to 2–3 yr based on the risk and protocol).
REFERENCES
Prostate Cancer Trialists’ Collaborative Group. Maximum androgen blockade in advanced prostate cancer: an overview of randomized trials. Lancet. 2000;255:1491–8.
Kollmeier MA, Zelefsky MJ. What is the role of androgen deprivation therapy in the treatment of locally advanced prostate cancer? Nat Clin Pract Urol. 2008;5(11):584–585.
MAYER–ROKITANSKY–KUSTER–HAUSER SYNDROME (ROKITANSKY—KUSTER–HAUSER SYNDROME)
DESCRIPTION A congenital absence of the vagina. The uterus is either abnormal or absent. The diagnosis is usually made when amenorrhea is noted in a normal pubertal XX person with a female phenotype. Renal and skelet al anomalies are a common association. The defect involves mesodermal development and the mesonephric kidney, the latter resulting in abnormalities in the paramesonephros (uterus and vagina) and in the metanephric kidney.
REFERENCE
Griffin JE, Edwards C, Madden JD, et al. Congenital absence of the vagina. The Mayer-Rokitansk-Kuster-Hauser syndrome. Ann Intern Med. 1976;85(2):224–236. Review.
MAYO CLINIC GRADING SYSTEM FOR PROSTATE CANCER
DESCRIPTION A grading system for prostate cancer that uses not only assessment of glandular architecture similar to Gleason’s grading system, but also histologic criteria. Grading is done on a scale of 1–4, with 4 having the worst prognosis. Cellular features, such as cytoplasmic-nuclear-nucleolar morphology, mitotic activity, and tumor invasiveness, are all used to assign grade.
REFERENCES
Kozlowski JM, Grayhack JP. Carcinoma of the prostate. In: Gillenwater JY, Grayhack JT, Howards SS, et al., eds. Adult and Pediatric Urology. 2nd ed. St. Louis, MO: Mosby; 1991.
Utz DC, Farrow GM. Pathologic differentiation and prognosis of prostatic carcinoma. JAMA. 1969;209(11):1701–1703.
McCUNE–ALBRIGHT SYNDROME
DESCRIPTION A syndrome characterized by a classic triad of fibrous dysplasia (cystic bone lesions), gonadotropin-independent precocious puberty, and cutaneous pigmentation with cafe-au-lait spots. It is caused by a mutation of chromosome 20q13, coding for the α-subunit of G-proteins that are involved with many hormone receptor signaling pathways.
SYNONYMS
• Polyostotic fibrous dysplasia
• Osteitis fibroso cystica
TREATMENT
Treatment is targeted at the specific endocrinopathy and may include:
• Hyperthyroidism surgery
• Adrenalectomy
• Aromatase inhibitors, anti-estrogens, and ant-iandrogens
REFERENCE
Collins MT, Singer FR, Eugster E. McCune-Albright syndrome and the extraskelet al manifestations of fibrous dysplasia. Orphanet J Rare Dis. 2012;7:S4. Published online May 24, 2012.
McGUIRE URINAL
DESCRIPTION An external male urine collection device consisting of a reusable latex urinal sheath that is either self-contained or attached directly to a leg bag. It is often supported by fabric suspensions in a jock-strap type fashion.
REFERENCE
Tanagho EA, McAininch JW. Neuropathic bladder disorders. In: Tanagho EA, McAininch JW, eds. Smith’s General Urology. 17th ed. New York, NY: McGraw-Hill; 2007.
MEATAL STENOSIS, URETHRAL, FEMALE
DESCRIPTION Distal urethral (meatal) stenosis is a recognized entity. Females with this condition present clinically with complaints ranging from UTI to enuresis. Distal urethral stenosis may be associated with the radiographic appearance of a prominent, collar-like bladder neck, which reflects generalized detrusor hypertrophy. When treatment is deemed necessary, the distal urethra is calibrated with bougies or female urethral sounds. (See also Section III: “Urethra, Meatus, Normal Caliber.”)
REFERENCE
Perlmutter AD, Colodny A, Harris PD, et al. Urethral meatal stenosis in female children simulating bladder-neck obstruction. J Pediatr. 1966;69(5):739–743.
MEATAL STENOSIS, URETHRAL, MALE
DESCRIPTION Most commonly seen after neonatal circumcision, this acquired condition is theorized to follow a postsurgical inflammatory reaction at the glans, resulting in an extremely narrow meatus. Meatal stenosis is usually not apparent until the child is toilet trained. Strength and/or direction of stream can be affected. Dysuria, frequency, incontinence, and hematuria are symptoms that have been associated with this condition. Meatal stenosis rarely causes obstructive changes in the urinary tract. Meatoplasty is the corrective procedure for those requiring surgical correction. (See also Section II: “Calibration, Meatus and Urethra.”)
REFERENCE
Brem J, Jaffee SR. Hidden meatal stenosis in male infants and children. Am Fam Physician (GP). 1970;2(2):72–73.
MECKEL–GRUBER SYNDROME (MECKEL SYNDROME)
DESCRIPTION Meckel–Gruber syndrome is a rare, lethal, autosomal recessive disorder with major characteristic features consisting of the triad of occipital encephalocele, polydactyly, and bilateral polycystic kidneys. Prenatal sonographic exam has been demonstrated to be of reliable diagnostic accuracy. For this reason, appropriate prenatal counseling is advocated for those at high risk.
REFERENCE
Sepulveda W, Sebire NJ, Souka A, et al. Diagnosis of the Meckel-Gruber syndrome at eleven to fourteen weeks’ gestation. Am J Obstet Gynecol. 1997;176(2):316–319.
MEDIAN BAR
DESCRIPTION Median bar refers to prostatic posterior commissural hyperplasia, an acinar hyperplasia involving the posterior bladder lip that produces a wide bar. Patients suffering enlargement of the middle lobe or posterior commissure are more likely to develop obstructive symptoms due to the tissue location, which easily obstructs the bladder neck. This explains the correlation between the size of the gland and the degree of obstruction.
REFERENCE
Randall A. Surgical Pathology of Prostatic Obstruction. Baltimore, MD: Williams & Wilkins; 1931.
MEDIAN RAPHE CYST
DESCRIPTION Median raphe cysts are uncommon congenital lesions of the male genitalia. Theories proposing its origin include the development of embryologic outgrows of epithelium after primary closure of urethral folds, or that they arise from epithelial remains caused by incomplete closure of the folds. Cysts can be found anywhere from the distal penis to anus at the midline. They are usually asymptomatic until adulthood, when they can be traumatized or secondarily infected, producing swelling, tenderness, and purulent discharge. Treatment is simple excision followed by primary closure.
REFERENCE
Krauel L. Median raphe cysts of the perineum in children. Urology. 2008;71(5):830–831.
MEDICATIONS THAT CAN IMPACT VOIDING FUNCTION
DESCRIPTION A variety of agents can impact on urinary function. Some can worsen incontinence, others can cause retention and difficulty voiding.
REFERENCE
Reprinted with permission from DuBeau CE. Urinary incontinence. In: Pompei P, Murphy JB, eds. Geriatrics Review Syllabus: A Core Curriculum in Geriatric Medicine. 6th ed. New York, NY: American Geriatrics Society; 2006: 185. Table based on data from Resnick NM. Geriatric medicine. In: Isselbacher JK, Braunwald E, Wilson JD, et al. eds. Principles of Internal Medicine. New York, NY: McGraw-Hill; 1994: p. 34.
MEDULLARY CYSTIC KIDNEY
DESCRIPTION A form of progressive renal disease with up to 75% of cases having medullary cysts, although it is primarily a tubulointerstitial disease. Juvenile nephronophthisis and medullary cystic disease are similar anatomically and clinically, but they have different modes of transmission and different clinical presentations. Juvenile nephronophthisis usually is inherited as an autosomal recessive trait (onset age: 6–20 yr), and medullary cystic disease typically is inherited as an autosomal dominant trait that presents after the 3rd decade. Patients present with polyuria and polydipsia due to salt wasting, a concentrating defect, anemia, and profound growth retardation. Juvenile nephronophthisis often is associated with disorders of the retina (ie, retinitis pigmentosa), skelet al abnormalities, hepatic fibrosis, and Bardet–Biedl syndrome (obesity, mental retardation, polydactyly, retinitis pigmentosa, and hypogenitalism). On US or CT, the medullary cysts can be seen with parenchyma and may appear hyperechogenic due to tubulointerstitial fibrosis.
SYNONYMS
• Juvenile nephronophthisis
• Uremic medullary cystic disease
• Salt-losing enteropathy
• Uremic sponge kidney
TREATMENT
Sodium replacement initially, with dialysis and transplantation later. The transplant graft appears to be resistant to the disease.
REFERENCE
Bernstein J, Gardner KD Jr. Familial juvenile nephronophthisis: Medullary cystic disease. In: Edelman CM Jr., ed. Pediatric Kidney Disease. Boston: Little, Brown; 1979:580.
MEGAPREPUCE (CONGENITAL MEGA PREPUCE)
DESCRIPTION Also known as megameatus intact-prepuce variant, this is a variant of hypospadias in which the ventral prepuce is intact and characterized by intermittent ballooning of the genital area. It may only be discovered following a dorsal slit at the time of circumcision. Associated anomalies include chordee, penoscrotal inversion, bifid scrotum, and cryptorchidism. One surgical repair consists of limited preputial resection of the phimotic ring, wide dissection of the outer prepuce to the base of the penis, fixation of the proximal outer prepuce to Buck’s fascia to create a new penoscrotal junction. Next step is unfurling and wide tailoring of the inner prepuce in the ventral midline to resurface the whole elongated penile shaft. A catheter is left in place for 5 or 6 days.
REFERENCES
Mesrobian HO. Urologic problems of the neonate: An update. Clin Perinatol. 2007;34(4):667–679.
Ruiz E, Vagni R, Apostolo C, et al. Simplified surgical approach to congenital megaprepuce: fixing, unfurling and tailoring revisited. J Urol. 2011;185(6 Issue):2487–2490.
MEGACALYCOSIS
DESCRIPTION A nonobstructive enlargement of the calyces due to a congenital malformation of the renal papillae. There is no dilation of the renal pelvis, and no evidence of UPJ obstruction. Found almost exclusively in males (6:1), it often presents in children due to a UTI workup or in adults with hematuria and renal calculi. The clinician must differentiate between hydronephrosis and UPJ obstruction.
TREATMENT
Not necessary. A diuretic renogram should fail to demonstrate any obstruction.
REFERENCE
Redman JF, Neeb AD. Congenital megacalycosis: a forgotten diagnosis? Urology. 2005;65(2):384–385.
MEGACYSTIS, CONGENITAL
DESCRIPTION A dilated, thin-walled bladder with a wide and poorly developed trigone. Because of the laterally displaced ureters, vesicoureteral reflux is commonly seen. Bladder contractility is normal, but most urine refluxes retrograde into the collecting system. Correction of the reflux often restores normal bladder dynamics. It is most often diagnosed on prenatal US. It is associated with megacystis-microcolon-intestinal hypoperistalsis syndrome, a rare congenital disorder characterized by a dilated, nonobstructive urinary bladder and hypoperistalsis of the GI tract.
TREATMENT
Correction of vesicoureteral reflux after 6 mo of age.
REFERENCE
Frimberger D, Kropp BP. Bladder anomalies in children. In: Wein AJ, et al., eds. Campbell-Walsh Urology. 9th ed. Philadelphia, PA: Saunders Elsevier; 2007.
MEGACYSTIS-MEGAURETER SYNDROME
DESCRIPTION The term megacystis-megaureter describes the radiologic appearance of a large-capacity, thin-walled bladder, and massive primary vesicoureteral reflux. The pathophysiology of these massively dilated ureters and the large-capacity bladder is the constant recycling of large volumes of refluxed urine. Bladder contractility is normal, even with a poorly developed trigone. Surgical correction of the reflux usually leads to a normal voiding pattern. (See also Section I: “Vesicoureteral Reflux, Pediatric.”)
TREATMENT
Correction of the reflux surgically should lead to a normal voiding pattern.
REFERENCE
Burbige KA, Lebowitz RL, Colodny AH, et al. The megacystis-megaureter syndrome. J Urol. 1984;131(6):1133–1136.
MEGALOURETHRA
DESCRIPTION Megalourethra is an extremely rare congenital deficiency of the mesodermal tissues of the phallus. It can best be described as a urethral diverticulum that affects the entire penile urethra. 2 types have been described, scaphoid and fusiform. Scaphoid megalourethras are more common and have an absence of corpus spongiosum, whereas fusiform megalourethras lack both spongiosum and corpora cavernosa. Often associated with lethal congenital anomalies, fusiform megalourethras are present in some stillborns. Transient obstruction during early development may be responsible for the fusiform type. With the scaphoid type, a failure of development of erectile tissue is present, a mesenchymal defect similar to the pathophysiology of prune belly syndrome (PBS). Many other conditions are associated, such as PBS, renal agenesis, hypospadias, cryptorchidism, and others. For PBS, urethrostomy may be needed secondary to bladder outlet obstruction and renal failure. In surgical repair of the scaphoid type, longitudinal reduction urethroplasty over a catheter to decrease urethral caliber or plication techniques can be used.
For the fusiform variant, each case is managed based on the amount of tissue present and the severity of disease (Image ).
REFERENCE
Vaghefi H, Simmons MN, Hsia MH, et al. Two extremes of the megalourethra spectrum. Urology. 2006;67:614–616.
MELANOMA, ADRENAL
DESCRIPTION Primary malignant melanoma of the adrenal gland is an established entity. It originates in the adrenal medulla from cells derived from the neural crest. Because of the high frequency of metastatic involvement of the adrenal by cutaneous and ocular melanomas, diagnosis can be difficult. Primary adrenal melanoma is a highly malignant tumor of middle age that often manifests as a painful flank mass. Distant lymph node metastases can be seen as a presenting sign. Treatment is not effective, with a mortality rate approaching 100% within 2 yr.
REFERENCE
Dao AH, Page DL, Reynolds VH, et al. Primary malignant melanoma of the adrenal gland. A report of two cases and review of the literature. Am Surgeon. 1990;56(4):199–203.
MELANOMA, GENITOURINARY
DESCRIPTION Malignant melanoma of the GU tract is rarely a primary disease. However, lesions of the penis, scrotum, and urethra can present as primary sites of disease. Secondary melanoma metastatic to the GU tract is a common autopsy finding. The majority of patients whose secondary melanoma is discovered clinically die of metastatic disease within 2 yr.
REFERENCE
Stein BS, Kendall AR. Malignant melanoma of the genitourinary tract. J Urol. 1984;132(5):859–868.
MELANOMA, URETHRAL
DESCRIPTION A malignant degeneration of melanocytes and nevus cells, primary malignant melanomas are rare. The urethra is the preferred site of the urinary tract and accounts for ∼4% of urethral cancers. A urethral melanoma is more likely to be primary compared with cases in the bladder or kidney. It is 3 times more common in women, more frequent in the white population, and most commonly affects the distal urethra. Presentation is similar to that of other urethral tumors, but melanuria is sometimes seen. It may be confused with urethral polyps, caruncles, mucosal prolapse, chancre, or more common malignant urethral tumors. It is most commonly unifocal. These are usually deeply invasive; local extension is common and inguinal lymph node metastases are present at diagnosis in 1/2 of the cases. Most patients do not survive >3 yr. (See also Section I: “Urethra, Carcinoma, General Considerations.”)
TREATMENT
• Limited data are available; most are treated with radical surgery and frequently bilateral lymph node dissection.
• Chemotherapy, immunotherapy, radiotherapy, or a combination of all 3 is experimental.
REFERENCE
Oliva E, Quinn TR, Amin MB, et al. Primary malignant melanoma of the urethra: A clinicopathologic analysis of 15 cases. Am J Surg Pathol. 2000;24(6):785–796.
MENKES SYNDROME (MENKES KINKY HAIR DISEASE)
DESCRIPTION A rare congenital disorder of copper metabolism with an X-linked recessive inheritance. Symptoms appear in the neonatal period and include hypothermia, poor feeding, and impaired weight gain. Neurogenic function progressively deteriorates. A colorless and friable hair is characteristically found. There tends to be a high incidence of GU conditions, including bladder diverticula, UTI, UPJ obstruction, vesicoureteral reflux, and cryptorchidism.
TREATMENT
• Parenteral copper therapy
• Bladder diverticula generally are treated with clean intermitent catheterization (CIC), as well as open cutaneous vesicostomy. Excision of the bladder diverticula is usually hazardous because of the generally poor health of these patients.
REFERENCE
Oshio T, Hino M, Kirino A, et al. Urologic abnormalities in Menkes’ kinky hair disease: Report of three cases. J Pediatr Surg. 1997;32(5):782–784.
MENOPAUSE, UROLOGIC CONSIDERATIONS
DESCRIPTION Menopause is the cessation of the menstrual cycle and is caused by reduced secretion of the ovarian hormones estrogen and progesterone. This causes a variety of symptoms, including those that affect the GU tract. Vaginal side effects such as dyspareunia (∼40%), itching, and vaginal dryness (∼55%) occur secondary to reduced estrogen and androgen secretions. A change in the pH of vaginal fluid from acidic to neutral occurs that increases urinary infections. Decreased estrogen contributes to collagen loss and subsequent pelvic organ prolapse and urinary symptoms. Urinary incontinence and irritative bladder symptoms occur in 20–40% of perimenopausal and postmenopausal women.
TREATMENT
• Topical estrogen therapy has been shown to decrease the incidence of urinary infections, increase bladder control with reduction in urge and irritative symptoms, and improve vaginal dryness and atrophy. It has no effect on stress urinary incontinence (SUI).
• The use of hormone therapy is generally on a short-term basis and only for symptomatic individuals. Although it has been shown to possibly have cardioprotective effects, an increase in breast cancer risk is also seen.
REFERENCE
Lobo RA. Menopause: Endocrinology, consequences of estrogen deficiency, effects of hormone replacement therapy, treatment regimens. In: Katz VL, et al. Comprehensive Gynecology. 5th ed. Philadelphia, PA: Mosby Elsevier; 2007.
MESOTHELIOMA, BENIGN, TESTICULAR TUNIC
DESCRIPTION Both a benign papillary, nonpapillary (adenomatoid tumor), and benign multicystic varieties exist. The nonpapillary tumor is the most common tumor of the epididymis and cord. All arise from the tunica vaginalis and are usually seen in young men 20–50 yr of age. The most common clinical presentation is associated with a painless scrotal mass or hydrocele. Benign multicystic mesothelioma has a recurrence rate of 27–75% in 3 mo–19 yr. (See also Section I: “Paratesticular Tumors.”)
REFERENCE
Aber A, Tahir A, Arumuham V, et al. Benign cystic mesothelioma: A rare cause for scrotal swelling. Case Rep Med. 2012;2012:572186.
MESOTHELIOMA, MALIGNANT, TESTICULAR TUNIC
DESCRIPTION Mesothelioma is a rare tumor (<100 cases reported), affecting the serosal surface of pleura, pericardium, peritoneum, and tunica vaginalis (an extension of the peritoneum). It usually presents as an incidental finding at the time of hydrocele surgery. It most commonly presents in the 5th–7th decades, although it has been reported in a patient 10 yo. Patients typically present with a hydrocele, but the initial physical exam rarely suggests malignancy. Metastatic spread occurs early via the lymphatic system to the paraaortic, inguinal, and supraclavicular nodes. The tumor spreads less commonly via the bloodstream to the lungs and liver. In the absence of metastatic spread, aggressive local surgery seems to yield the best results. The role of adjuvant chemotherapy and radiotherapy is less clear. (See also Section I: “Paratesticular Tumors.”) (Image )
REFERENCE
Brimo F, Illei PB, Epstein JI. Mesothelioma of the tunica vaginalis: A series of eight cases with uncertain malignant potential. Modern Pathology. 2010;21:1165–1172.
METABOLIC STONE EVALUATION (24-HR URINE STUDIES)
DESCRIPTION Patients with urolithiasis should be encouraged to retrieve stones or stones removed surgically should be submitted for stone analysis. The extent of further evaluation is somewhat controversial. It is generally agreed that all patients who present with nephrolithiasis undergo a basic evaluation to rule out a systemic disease. This limited evaluation include history, physical exam, imaging for any residual stones, electrolytes, creatinine, calcium, uric acid, phosphorus, stone analysis and urinalysis, including urine pH. This may diagnose uncommon, but potentially serious, systemic conditions (eg, primary hyperparathyroidism or distal renal tubular acidosis). Patients with complex anatomy should undergo a comprehensive evaluation with their first episode of urolithiasis. In contrast, a comprehensive metabolic stone evaluation goes beyond the limited evaluation. The results of the metabolic stone evaluation can provide information on the best strategy to reduce future stone formation and allow monitoring of therapeutic interventions.
• Two 24-hr urine collections on a random diet with components noted below with initial quantitative cystine determination (optional)
• Serum calcium, phosphorus, uric acid, HCO3, BUN, creatinine, albumin, alkaline phosphate, intact PTH (optional), 1,25-di-OH-vitamin D2 (optional)
REFERENCE
Paterson RF. Arguments for a comprehensive metabolic evaluation of the first-time stone former. Can Urol Assoc J. 2010;4(3):209–210.
METABOLIC SYNDROME, UROLOGIC CONSIDERATIONS
DESCRIPTION An increasingly more prevalent disease affecting ∼22% of American adults, metabolic syndrome is characterized by having any 3 of the following: Abnormal waist circumference, hypertriglyceridemia, low HDL, hypertension, or abnormal fasting glucose parameters. Sexual dysfunction can occur, including hypogonadism and erectile dysfunction (ED). Many patients have a low urinary pH, thus increasing the risk of uric acid stones. Subclinical Cushing syndrome accounts for 3–5% of metabolic syndrome and should be in the differential diagnosis. ADT can contribute to metabolic syndrome.
SYNONYMS
• Syndrome X
• Insulin resistance syndrome
• Obesity dyslipidemia syndrome
TREATMENT
• Lifestyle modifications with dietary changes, increased physical activity, and smoking cessation
• Obesity: Goal of gradual 5–10% weight reduction. Consider bariatric surgery in extreme cases if conservative management fails.
• Pharmacologic therapy: aimed at hypertension, hyperlipidemia/dyslipidemia, other
• Impaired glucose tolerance: initial management with diet and exercise
– Prothrombotic states: Consider low-dose aspirin in high coronary artery disease risk
– Testosterone for hypogonadism may have protective cardiovascular effects (controversial)
• Oral hydration and urine alkalinization can be considered for uric acid stone formers.
REFERENCE
Tukaye DN. Metabolic syndrome. In: Domino FJ, ed. 5 Minute Clinical Consult 2014. 22nd ed. Philadelphia, PA: Wolters Kluwer; 2014.
METANEPHRIC ADENOFIBROMA, KIDNEY (NEPHROGENIC ADENOFIBROMA)
DESCRIPTION A pediatric benign renal tumor with stromal features resembling congenital mesoblastic nephroma. The epithelial component has varying levels of activity ranging from inactive metanephric adenoma to Wilms tumor. Some masses contain areas identical to papillary RCC. Lesions with a Wilms tumor component occur at a young age (mean of 12 mo). No tumors have recurred after nephrectomy, but all have been treated with Wilms tumor chemotherapy. There has been 1 case described with nodal metastasis of the papillary RCC component of their tumor.
REFERENCE
Argani P. Metanephric neoplasms: The hyperdifferentiated, benign end of the Wilms Tumor spectrum? Clin Lab Med. 2005;25(2):379–392.
METANEPHRIC ADENOMA
DESCRIPTION A recently recognized renal tumor originally described in 1980; it bears a cytologic resemblance to early metanephric tubular differentiation and to the metanephric hamartomatous element of nephroblastomatosis. Fewer than 100 cases have been reported, with a 2:1 female-to-male predominance. Most cases present in the 5th–6th decades of life, and the lesion is often discovered incidentally. An association with polycythemia has been reported in 12% of the cases that resolves after surgical resection. These adenomas are typically unilateral and rarely multifocal. The majority are either unencapsulated or have only a limited and discontinuous pseudocapsule. It is largely regarded as a benign neoplasm but in 1 case lymph node metastases were reported. It cannot be differentiated from RCC on imaging studies. WT1 and CD57 immunohistochemical staining aids in the diagnosis of metanephric adenoma (Image ).
REFERENCE
Hartman DJ, MacLennan GT. Renal metanephric adenoma. J Urol. 2007:178(3):1058.
METAPYRONE TEST
DESCRIPTION Cushing syndrome describes the symptom complex caused by excess circulating glucocorticoids. Metapyrone is a blocking agent used to reduce the secretion of functional steroids, thereby lessening the severity of symptoms. Metapyrone blocks the conversion of 11-deoxycortisol to cortisone. It is a diagnostic test for hypothalamic–pituitary ACTH function:
• Day 1: Control period: Collect 24-hr urine to measure 17-hydroxycorticosteriods or 17-ketogenic steroids.
• Day 2: ACTH test: 50 units ACTH infused over 8 hr and measure 24-hr urinary steroids.
• Days 3–4: Rest period.
• Day 5: Administer metyrapone with milk or snack. (Adult: 750 mg PO q4h for 6 doses; Pediatric: 15 mg/kg q4h for 6 doses [min 250 mg dose]).
• Day 6: Determine 24-hr urinary steroids.
• Normal 24-hr urine 17-OHCS is 3–12 mg; following ACTH, it increases to 15–45 mg/24 hr; normal response to metyrapone is a 2–4-fold increase in 17-OHCS excretion; drug interactions with phenytoin, cyproheptadine, and estrogens may lead to subnormal response.
REFERENCE
Scott HW Jr., Orth DN. Hypercortisolism. In: Surgery of the Adrenal Glands. Philadelphia, PA: JB Lippincott; 1990.
MEYER–WEIGERT LAW
DESCRIPTION In cases in which separate ureteric buds on the same mesonephric duct form a completely duplicated collecting system, separate investigators (Weigert and then Meyer) noted that there exists a consistent relationship between the upper and lower pole orifices as they relate to 1 another on the trigone. The caudad, or distally placed, orifice actually drains the upper pole moiety; whereas the cranial, or superior, orifice drains the lower pole moiety. The distal orifice is more medial on the trigone, as opposed to the laterally placed cranial orifice. This is a reliable rule for cases of ureteral duplication.
REFERENCE
Glassberg KI, Braren V, Duckett JW, et al. Suggested terminology for duplex systems, ectopic ureters and ureteroceles. J Urol. 1984;132 (6):1153–1154.
MIBG SCAN
DESCRIPTION A form of molecular imaging using metaiodobenzylguanidine (MIBG), an analog of guanethidine. MIBG accumulates into cells via norepinephrine transporters and is collected into secretory granules. It is useful in identifying primary and metastatic pheochromocytoma, paraganglioma, and neuroblastoma.
REFERENCE
Chen CC, Carrasquillo JA. Molecular imaging of adrenal neoplasms. J Surg Onc. 2012;106:532–542.
MICHAELIS–GUTMANN BODIES
DESCRIPTION Michaelis–Gutmann bodies are the pathognomonic finding in the benign inflammatory process known as malakoplakia. Light microscopy demonstrates a granulomatous inflammatory process, characterized by the accumulation of large mononuclear cells with abundant granular cytoplasm and PAS-positive calcific intracytoplasmic inclusions (so-called Michaelis–Gutmann bodies). On electron microscopy, such inclusions appear as concentric lamellated structures with a mineralized core (Image ).
REFERENCE
Lambird PA, Yardley JH. Urinary tract malakoplakia: Report of a fatal case with ultrastructural observations of Michaelis-Gutmann bodies. Johns Hopkins Med J. 1970;126(1):1–14.
MICROCYSTIC/NESTED VARIANT UROTHELIAL CARCINOMA
DESCRIPTION Microcystic and nested variant urothelial carcinoma are rare histologic subtypes of bladder cancer that appear similar to benign conditions of the bladder, however demonstrate aggressive behavior. Microcystic urothelial cancer has an inverted growth pattern that resembles cystitis cystica. It has been identified in bladder, upper tract, and prostatic urethra. Nested variant urothelial carcinoma is easily mistaken for reactive von Brunn nests. Lesions have a low-grade appearing cytology even when invasive. Lymphovascular invasion (LVI) is usually present at the time of diagnosis (Image ).
REFERENCE
Shanks JH, Iczkowski KA. Divergent differentiation in urothelial carcinoma and bladder cancer subtypes with selected mimics. Histopathology. 2009;54:885–900.
MICROLITHIASIS, TESTIS
DESCRIPTION Testicular microlithiasis is an uncommon condition characterized by the presence of calcifications within degenerating seminiferous tubules. There is a reported incidence of between 2 and 6% of males. Microlithiasis is often found in conjunction with other testicular pathologies, with testicular malignancy being the most concerning, however, there are conflicting reports. Currently, no guidelines exist for follow-up of patients diagnosed with microlithiasis of the testis. Recommendations range from no follow-up to a staging workup for testicular carcinoma. At a minimum, testicular self-exams are important and annual physical exam by a physician is recommended. Some authors suggest annual exam by a urologist in conjunction with annual ultrasound for patients with risk factors for testicular cancer (Image ).
REFERENCE
Rashid HH, Cos LR, Weinberg E, et al. Testicular microlithiasis: A review and its association with testicular cancer. Urol Oncol. 2004; 22(4):285–289.
MICROPAPILLARY BLADDER CANCER
DESCRIPTION A variant of bladder cancer 1st described in 1994. The histologic features closely resemble papillary serous carcinoma of the ovary. It accounts for 0.7–2.2% of all urothelial tumors and is nearly always associated with an advanced stage of disease and aggressive clinical course. A recent review of 100 consecutive patients at MD Anderson Cancer Center indicated an average age of 64.7 yr, with a male-to-female ratio of 10:1. 5 and 10-yr survivals of 51% and 24%, respectively. Intravesical therapy appears to be ineffective. Radical cystectomy provides a chance of cure in these patients. (See also Section I: “Bladder Cancer, General.”) (Image )
TREATMENT
Expeditious radical cystectomy in patients with surgically resectable disease
REFERENCE
Kamat AM, Dinney CP, Gee JR, et al. Micropapillary bladder cancer: A review of the University of Texas MD Anderson Cancer Center experience with 100 consecutive patients. Cancer. 2007;110(1):62–67.
MICTURITION SYNCOPE
DESCRIPTION Syncopal episodes occurring during voiding are known as micturition syncope. This was originally though to be a disorder of young healthy men, however additional studies have found micturition syncope to span ages and gender. Several mechanisms have been suggested in the literature. 1 is that decompression of the bladder results in a decreased intra-abdominal pressure therefore decreasing blood return and causing a sudden decrease in cerebral blood flow. Another is that increased vagal tone during voiding results in a syncopal episode. Finally, micturition syncope could be an orthostatic event as a result of waking from sleep that occurs during the 1st void of the day immediately after wakening. Rarely, micturition syncope can be a symptom of a pheochromocytoma/paraganglioma of the bladder. Further investigation with urinalysis and cystoscopy are warranted in addition to workup of a cardiovascular source of syncope.
REFERENCE
Kapoor WN, Peterson JR, Karpf M. Micturition syncope. JAMA. 1985;253:796–798.
MILK OF CALCIUM, URINARY TRACT
DESCRIPTION The crystallization of calcium salts without actual stone formation. These usually accumulate in simple renal cysts or calyceal diverticula. On ultrasound, it is an echogenic focus or layer within the cyst. On IVP, it appears as a crescent-shaped density whose meniscus may adjust relative to patient positioning.
TREATMENT
Endoscopic, percutaneous, or ablative procedures may be performed if clinically indicated (ie, pain, infection).
REFERENCE
Sidhu R, Bhatt S, Dogra V, et al. Renal colic. Ultrasound Clin. 2008;3:159–170.
MILK–ALKALI SYNDROME
DESCRIPTION Hypercalcemia and alkalosis associated with the ingestion of large amounts of milk and antacids containing calcium and absorbable alkali. Patients can develop nephrocalcinosis and renal insufficiency, but typically do not have hypercalciuria. The associated vomiting and dehydration can produce further volume contraction and alkalosis. (See also Section I: “Nephrocalcinosis, Adult.”)
TREATMENT
• Withdrawal of milk and alkali, with gentle hydration to lower serum calcium
• Vigorous hydration can result in rebound hypocalcemia due to the chronic suppression of the parathyroid glands
REFERENCE
Smith SG. Milk-alkali syndrome. In: Domino FJ M, ed. The 5-Minute Clinical Consult 2014. Philadelphia, PA: Wolters Kluwer/Lippincott Williams & Wilkins; 2014.
MITROFANOFF PRINCIPLE
DESCRIPTION A surgical procedure, originally described by Mitrofanoff, in which the appendix is excised with a button of cecum, reversed, and tunneled to create a catheterizable channel with a reported continence rate of 93–100%. Stomal stenosis is an early complication affecting 7–24% within 3 yr in published series.
REFERENCE
Harris CF, Cooper CS, Hutcheson JC, et. al. Appendicovesicostomy: The mitrofanoff procedure – A 15 year perspective. J Urol. 2000;163(6):1922–1926.
MIXED EPITHELIAL STROMAL TUMOR OF THE KIDNEY (MESTK)
DESCRIPTION MESTK is a subset of benign renal tumors composed mainly of smooth muscle cells in which epithelial structures are embedded. It is usually found in middle-aged and perimenopausal women. Grossly, MESTK is well-circumscribed but unencapsulated, and cystic on a cut surface. Microscopically, it is composed both of epithelial structures similar to renal tubules and stroma comprising nonspecific spindle cells. The differential diagnosis for these tumors includes cystic nephroma and cystic partially differentiated nephroblastoma.
REFERENCE
Michal M, Hes O, Bisceglia M, et al. Mixed epithelial and stromal tumors of the kidney. A report of 22 cases. Virchows Arch. 2004;445(4):359–67.
MOLLUSCUM CONTAGIOSUM
DESCRIPTION A benign, self-limited skin tumor or papular eruption caused by a virus. Infection occurs after breakage of the skin and characteristically begins as a small papule. When mature, it is a discrete 2–5 mm smooth, dome-shaped, pearly or flesh-colored nodule that is often umbilicated. Single to hundreds of lesions may track alone the line of a scratch. In adults, they occur on the trunk, thighs, and pubic areas. Lesions usually disappear by themselves within 6–12 mo, although this may take up to 4 yr with impaired cell-mediated immunity. Diagnosis is usually clinical, but brick-shaped virions can sometimes be seen under negative-stain electron microscopy. Henderson–Paterson bodies are characteristically seen on pathology. (See also Section I: “Sexually Transmitted Diseases [STDs], General.”)
TREATMENT
• Observation is reasonable for nongenital lesions.
• Curettage is useful for treating a few lesions; scarring may develop.
• Liquid nitrogen therapy, cantharidin 0.7%, tretinoin 0.025% gel, or 0.1% cream; laser therapies are also common.
REFERENCE
Damon I. Other poxviruses that infect humans: Parapoxvirus, molluscum contagiosum, and tanapox. In: Mandell GL, et al., eds. Mandell, Douglas, & Bennett’s Principles and Practice of Infectious Diseases.6th ed. Philadelphia, PA: Elsevier; 2005.
MONDOR DISEASE
DESCRIPTION Mondor disease is superficial thrombophlebitis of the dorsal vein of the penis. It is typically diagnosed in young males after excessive sexual activity and can be diagnosed in older males due to venous obstruction secondary to bladder distention. Physical exam typically reveals a tender palpable cord on the dorsal surface of the penis as well as distal penile edema. Treatment is conservative with abstinence of sexual activity until completely resolved. Anticoagulation and antiplatelet medications have not been shown to be of benefit. Vein stripping surgery is indicated for patients with associated cellulitis.
REFERENCE
Dicuio M, Pomara G, Cuttano MG, et al. Penile Mondor’s disease after intensive masturbation in a 31 and a 33 year old man. Thromb Haemost. 2003;90(1):155–156.
MONFORT TECHNIQUE
DESCRIPTION A type of abdominal wall reconstruction in patients with prune belly syndrome. This technique utilizes an elliptical incision that preserves the umbilicus and thickens and strengthens the anterior abdominal wall. Full-thickness resection of skin from the central abdomen is performed, and the anterior wall is sutured in a double-breasted fashion preserving vascularity and the umbilicus. This technique offers excellent exposure for concomitant intra-abdominal surgery.
REFERENCE
Monfort G, Guys JM, Bocciardi A, et al. A novel technique for reconstruction of the abdominal wall in the prune belly syndrome. J Urol. 1991;146(2):639–640.
MONTI PROCEDURE
DESCRIPTION Also known as the Monti ileovesicostomy, a technique most often used in children to create a continent catheterizable stoma. A short segment of bowel (2–3 cm of ileum) is incised along the antimesenteric border and then closed transversely to create a uniform tube that can be tunneled into the bladder and out through the abdominal wall. This allows preservation of the appendix for the Malone antegrade continent enema (MACE) procedure. A review of 199 patients undergoing Monti ileovesicostomy at a single institution reported a revision rate of 8.5% and a continence rate of 96.5% with mean follow-up of 28 mo.
REFERENCE
Rink RC, Dussinger AM, Gitlin J, et al. Updated Experience with the Monti catheterizable channel. Urology. 2008;72(4):782–785.
MORRIS SYNDROME
DESCRIPTION An intersex disorder that affects 1 in 20,000 live male births; it is caused by a mutation in the androgen receptor gene located on the long arm of the X chromosome. This prevents appropriate androgen binding and/or function. If complete androgen insensitivity occurs, the child will appear to have a normal female phenotype and the testes are located internally. Many children are diagnosed at the time of hernia repair as infants or not diagnosed until puberty during an evaluation for primary amenorrhea.
SYNONYMS
• Testicular feminization syndrome
• In class of male pseudohermaphroditism
REFERENCE
Hyun G, Kolon TF. A practical approach to intersex in the newborn period. Urol Clin N Am. 2004;31(3):435–443.
MOSKOWITZ VAGINAL PROLAPSE REPAIR
DESCRIPTION Through a transabdominal exposure, the procedure entails closing the cul-de-sac through placement of a series of purse-string sutures. The procedure was initially described to treat rectal prolapse by securing the rectum to the fixed vagina, and the same logic has been used to correct vaginal prolapse by fixing it to the rectum. Unfortunately, the rectum is not well anchored. (See also Section I: “Pelvic Prolapse [Cystocele and Enterocele].”)
REFERENCE
Raz S, et al. Vaginal reconstructive surgery for incontinence and prolapse. In: Walsh PC, Retik AB, Vaughan ED, et al., eds. Campbell’s Urology. 7th ed. Philadelphia, PA: Saunders; 1998:1066–1094.
MOSTOFI (WHO) GRADING SYSTEM, PROSTATE CANCER
DESCRIPTION Traditional prostate cancer grading system, generally replaced by the Gleason grading system:
• Grade I: Well differentiated, with slight nuclear anaplasia
• Grade II: Moderately to poorly differentiated, with moderate nuclear anaplasia
• Grade III: Poorly differentiated, with marked nuclear anaplasia, or undifferentiated carcinoma
SYNONYM
World Health Organization Grading System
REFERENCE
Mostofi FK. Grading of prostatic carcinoma. Cancer Chemother Rep. 1975;59(Pt I):111–117.
MOWAT–WILSON SYNDROME
DESCRIPTION A syndrome of multiple congenital anomalies due to a heterozygous mutations or deletions in ZEB2, or Zinc finger E-box-biding homeobox 2 gene. It is generally discovered on genetic workup for Hirschsprung disease. Patients present with a distinct facial phenotype, mental retardation, epilepsy, agenesis of corpus callosum, and congenital heart defects. Roughly 50% of patients have genitourinary anomalies with hypospadias being the most prominent (52%). Another common anomaly is cryptorchidism (36%). Bifid scrotum, vesicoureteral reflux and micropenis are rare but have been reported.
REFERENCE
Garavelli L, Mainardi PC. Mowat- Wilson syndrome. Orphanet J Rare Dis. 2007;2:42.
MUCORMYCOSIS, GENITOURINARY
DESCRIPTION A fungal infection that usually affects immunocompromised patients. Patients receiving hemodialysis and deferoxamine are at particular risk for disseminated disease. The kidneys are the organs most often involved in the GU system, but penile involvement has also been reported. The course is usually fatal. (See also Section I: “Fungal Infections, Genitourinary.”)
TREATMENT
Amphotericin B systemically; nephrectomy for involved kidney
REFERENCE
Wise GJ, Freyle J. Changing patterns in genitourinary fungal infections. AUA Update Series. Vol. XVI, Lesson 1; 1997.
MUCOSURIA (MUCINURIA)
DESCRIPTION Passage of mucous during urination. This is a normal finding in patients who have undergone bladder replacement surgery using bowel segments. Mucosuria can be a symptom of mucinous adenocarcinoma of the urinary tract, most commonly of the urachus however mucin producing tumors of the prostate and renal pelvis have been reported. Other sources of mucin production in the bladder include invasive colorectal cancer and colovesical fistulas. (See also Section I: “Bladder Cancer, Adenocarcinoma.”)
REFERENCE
Bohman KD, Osunkoya AO. Mucin-producing tumors and tumor-like lesions involving the prostate: A comprehensive review. Adv Anat Pathol. 2012;19(6):374–387.
MUIR–TORRE SYNDROME
DESCRIPTION An autosomal dominant skin condition characterized by tumors of the sebaceous gland or keratoacanthoma associated with ≥1 visceral malignancies including colorectal, endometrial, urologic, and upper GI. Usually considered a subtype of hereditary nonpolyposis colorectal cancer syndrome; ∼25% of the visceral cancers are associated with the urogenital tract, the most common of which are urothelial carcinoma.
REFERENCE
Ponti G, Ponz de Leon M. Muir-Torre syndrome. Lancet Oncol. 2005;6:980–987.
MULBERRY STONES
DESCRIPTION A term that refers to the surface appearance of irregular calcium oxylate dihydrate stones often seen in the bladder. Based on their less well-developed spikes than seen on jackstones; the spikes possess more of a mamillated appearance.
REFERENCE
Amis ES, Newhouse JH, eds. Essentials of Uroradiology. 1st ed. Boston: Little-Brown; 1991:224.
MULCAHY PROTOCOL
DESCRIPTION Infection of a penile prosthesis is suspected when there is local pain and erythema, fever and cutaneous fixation of the prosthesis components. In this situation there are 2 main options. The 1st is to remove the prosthesis and reinsert it at least 6–8 mo later. This repeat surgery can be difficult due to formation of scar tissue in the corpora. Another option is to remove the prosthesis, perform a copious antibiotic washout of the corpora cavernosa with an antibiotic solution, then place a ‘‘tutor’’ cylinder inside the corpora to prevent shortening and scarring. Another approach to the management of an infected penile prosthesis is the Mulcahy protocol. This involves complete removal of the infected part of the prosthesis and all other components followed by the use of the specific Mulcahy salvage procedure outlined below with reinsertion of a new penile prosthesis in the same sitting with a reported success rate of 85%. (See also Section I “Penile Prosthesis Problems [Infection/Extrusion/Malfunction]”.)
• Remove all prosthetic parts and foreign material
• Irrigate wounds using 5 antiseptic solutions:
– Antibiotic solution (1 g vancomycin and 80 mg gentamicin in 1 L of normal saline)
– 1/2 strength hydrogen peroxide
– Pressure washing with 1 g vancomycin and 80 mg gentamicin in 5 L irrigation
– 1/2 strength Povidone-iodine (Betadine or similar)
– Antibiotic solution rinse
• Change gowns, gloves, surgical drapes, and instruments immediately before prosthesis insertion
• Insert new prosthesis
• Close wounds with no drains or catheters
• Administer oral antibiotics for 1 month
REFERENCES
Mulcahy JJ. Current approach to the treatment of penile implant infections. Ther Adv Urol. 2010;2(2):69–75.
Natali A. Management of the complications of penile prosthesis implantation. World J Men’s Health. 01/2010;7(3). doi:10.1016/j.jomh.2010.07.003
MÜLLERIAN DUCT REMNANTS AND SYNDROME (PMDS)
DESCRIPTION Refers to the persistence of the müllerian duct structures (uterus, fallopian tubes) in the genotypically and phenotypically normal male. The remnants persist due to the absence of müllerian inhibiting substance. It is an autosomal recessive inherited disorder. Patients present with cryptorchidism and hernia, and the persistent müllerian structures are found within the hernia sac. Increasing evidence is mounting that persistent müllerian structures are at risk for malignant transformation. 11 cases of malignancy have been reported in the literature out of 200 reported cases of persistent Müllerian dcut syndrome (PMDS).
SYNONYMS
• Prostatic utricular cyst
• Müllerian duct cyst (Image )
REFERENCE
Farikullah J, Ehtisham S, Nappo S, et al. Persistent Müllerian duct syndrome: lessons learned from managing a series of eight patients over a 10-year period and review of literature regarding malignant risk from the Müllerian remnants. BJU Int. 2012;110(11 Pt C):E1084–E1089.
MULTILOCULAR CYSTIC NEPHROMA (CYSTIC NEPHROMA, MULTILOCULAR CYST)
DESCRIPTION A round, well-encapsulated multilocular cystic mass whose septa are composed of well-differentiated tissues, without blastemal elements. The current thinking is that multilocular cystic nephroma is at the benign end of a spectrum that includes cystic partially differentiated nephroblastoma (CPDN) and Wilms tumor on the malignant end. Grossly, multilocular cystic nephroma and CPDN look identical. The contents of the cysts consist of either clear to yellow fluid or thick myxomatous gel. The lesion is usually solitary but rarely can be multiple. Cystic nephroma presents in a bimodal age distribution of 3 mo–2 yr (2:1 male-to-female) and in adulthood (8:1 female-to-male). Children usually present with a palpable mass and adults with pain, hematuria, or infection. Imaging cannot distinguish between cystic nephroma and CPDN. The lesion often is close to the renal pelvis, and herniation of the renal pelvis is a pathognomonic finding on IV urography, CT, or MRI. The nephromas contain noncommunicating cysts with thin septa separating the cysts. On US, multiple anechoic spaces are seen, separated by hyperechoic septa. CT reveals a well-marginated, rounded, or polycyclic cortical mass that extends beyond the normal renal outline. Enhancement of the septa may be seen due to the presence of thin vessels. Imaging cannot reliably predict malignant potential.
SYNONYMS
• Cystic kidney, cystic nephroma
• Focal polycystic kidney
• Multicystic or cystic adenoma
TREATMENT
• Partial nephrectomy or radical nephrectomy is indicated.
• Follow-up is required because of local recurrence (Image ).
REFERENCE
Stamatiou K, Polizois K, Kollaitis G, et al. Cystic nephroma: A case report and review of the literature. Cases J. 2008;1(1):267.
MULTIPLE ENDOCRINE NEOPLASIA (MEN I, MEN II)
DESCRIPTION A group of inherited syndromes primarily consisting of endocrine tumors of both benign and malignant nature. MEN syndrome lesions are of urologic interest because of the possibility of adrenal involvement, hyperparathyroidism, renal stones, and hyperlactatemia:
• MEN I (Wermer syndrome): Autosomal dominant condition with neuroendocrine parathyroid, pancreas, duodenal, and pituitary lesions. Cutaneous tumors may also be seen (angiofibromas, others). Hyperparathyroidism is the most common presentation of this syndrome, but overall this is a rare cause of hyperparathyroidism in the general population. Pituitary lesions may cause hyperprolactinemia and ACTH-producing lesions.
• MEN II (Sipple syndrome): Autosomal dominant:
– Type IIA triad: Pheochromocytoma, medullary carcinoma of the thyroid, parathyroid adenoma
– Type IIB: Pheochromocytoma, medullary carcinoma of the thyroid (but not parathyroid hyperplasia) with mucosal neuromas, intestinal ganglioneuromas, and occasionally marfanoid habitus. Some literature refers to this as MEN III (mucosal neuroma syndrome).
REFERENCE
Callender GG, Rich TA, Perrier ND. Multiple endocrine neoplasia syndromes. Surg Clin N Am. 2008;88(4):863–895.
MULTIPLE MYELOMA, UROLOGIC CONSIDERATIONS
DESCRIPTION A malignant proliferation of plasma cells derived from a single clone. The classic triad involves marrow plasmacytosis, lytic bone lesions, and a serum and/or urine M component. Renal failure occurs in 25% of patients. Hypercalcemia is the most common cause, but hyperuricemia is also present and a likely cause. Tumor lysis syndrome is uncommon with multiple myeloma. There may be tubular precipitation of light-chain proteins (myeloma kidney), urinary obstruction due to uric acid or calcium-containing stones, or recurrent pyelonephritis. Glomerular, tubular, and interstitial involvement can cause renal insufficiency. The development of a myeloma kidney can lead to adult Fanconi syndrome, which is a type II proximal renal tubular acidosis. NSAIDs are to be avoided. Renal failure is rare but has been reported after the use of contrast agents in patients with multiple myeloma.
REFERENCE
Sakhuja V, Jha V, Varma S, et al. Renal involvement in multiple myeloma: A 10-year study. Ren Fail. 2000;22(4):465–477.
MUMPS ORCHITIS
DESCRIPTION Mumps is a single-stranded RNA (paramyxo) virus. After the prodromal period, 1 or both parotid glands begin to enlarge. Mumps orchitis follows the development of parotitis by 4–7 days, with about 20% of males developing orchitis (10% bilateral and 80–90% unilateral). It has been reported following mumps vaccination. The presentation is high fever, testicular pain, and swelling. The management of mumps orchitis is supportive (bedrest, scrotal support, analgesics) with resolution in about 7 days. Unilateral testicular atrophy occurs in 60%. Impaired fertility can affect up to 13%, but sterility is rare. (See also Section I: “Orchitis, General.”)
REFERENCE
Masarani M, Wazait H, Dinneen M. Mumps orchitis. J R Soc Med. 2006;99(11):573–575.
MURCS ASSOCIATION (MüLLERIAN DUCT, RENAL, AND CERVICAL VERTEBRAL DEFECTS)
DESCRIPTION MURCS association consists of a nonrandom association of müllerian duct aplasia, renal aplasia/agenesis, and cervicothoracic somite dysplasia. The incidence of cervicothoracic vertebral defects, especially from C5–T1, is 80%. Other abnormalities may include Sprengel deformity, upper limb defects, and moderately frequent rib anomalies. It is the 2nd most frequent cause of primary amenorrhoea after Turner syndrome.
REFERENCE
Braun-Quentin C, Billes C, Böwing B, et al. MURCS association: Case report and review. J Med Genet. 1996;33(7):618–620.
MUSCLE FLAP TYPES, UROLOGIC CONSIDERATIONS
DESCRIPTION Muscle flaps are a reconstructive technique using local or distant muscle donor sites to provide tissue coverage in complex reconstructive procedures. The most simple muscle flaps are local and regional flaps where blood supply of the muscle is not interrupted when the flap is repositioned to its new location. Pedicle and micro vascular free flaps are more complicated forms of tissue transfer that are finding new indications in reconstructive urologic procedures. Tissue transfer has become increasingly used in centers for complex repair of fistula disease following radiation. In addition, clinical study has shown latissimus dorsi transferred to acontractile detrusor tissue with microsurgical coaptation of the thoracodorsal nerve to low intercostal nerves innervating the rectus abdominus has restored voluntary voiding in patients with detrusor areflexia.
REFERENCE
Ninkovic M, Dabernig W. Flap technology for reconstructions of urogenital organs. Curr Opin Urol. 2003;13:483–488.
MUSTARDé HYPOSPADIAS REPAIR
DESCRIPTION A more extensive Mathieu technique in which the ventral flap is tubularized to form a neourethra and then transposed distally. The glans wings are again approximated over the neourethra.
REFERENCE
Belman AB. The modified Mustardé hypospadias repair. J Urol. 1982;127(1):88–90.
MYCOPLASMA GENITALIUM INFECTION
DESCRIPTION Mycoplasma genitalium is a common organism that resides within the genital tracts of both men and women. However, it may be a cause of chronic prostatitis in men or urgency and frequency in women. Identifying and culturing this organism is difficult. Initial treatment includes doxycycline 100 mg BID for 2 wk or azithromycin 1 g in a single dose.
REFERENCE
Moi H, Reinton N, Moghaddam A. Mycoplasma genitalium is associated with symptomatic and asymptomatic nongonococcal urethritis in men. Sex Transm Infect. 2009;85(1):15–18.
MYCOPLASMA HOMINIS, URINARY TRACT INFECTION
DESCRIPTION Mycoplasma hominis commonly resides in the genital tracts of both men and women. This organism is often found in women with bacterial vaginosis and can be a cause of PID and dyspareunia. It is generally susceptible to tetracycline and quinolones.
REFERENCE
Kenny GE. Genital mycoplasmas: Mycoplasma genitalium, Mycoplasma hominis, and Ureaplasma species. In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Bennett, & Dolin: Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, PA: Elsevier, 2005:2280–2282.
MYOCUTANEOUS FLAPS
DESCRIPTION Myocutaneous flaps, such as rectus flap, gracilis flap, or tensor fascia flap, can be utilized during urologic reconstructive surgery. Common applications are for skin coverage during ilioinguinal node dissections for penile cancer, closure of urinary fistulae, and reconstruction after Fournier gangrene:
• Rectus abdominis flap: The blood supply of the rectus abdominis is the superior and deep inferior epigastric vessels. The deep superior epigastric vessels are not utilized as a vascular pedicle for the free flap because of their smaller caliber and a greater amount of skin can be transferred by relying on the interior epigastric pedicle.
• Gracilis flap: The origin of the gracilis muscle is the ischium and inferior ramus of the pubis and the insertion is the medial tibia. The gracilis muscle is 4–8 cm wide and is harvested from the inner thigh. It can be utilized either as a muscle flap or myocutaneous flap and leaves the patient without any functional deficit. The nerve supply to the gracilis muscle is a branch of the obturator nerve, and its blood supply is a single artery from the profunda femoral system.
• Tensor fascia lata flap: The tensor fascia lata can be harvested from the lateral aspect of the upper leg. The vascular pedicle is comprised of the transverse branch of the lateral circumflex femoral artery, and the sensory supply is the lateral femoral cutaneous nerve of the thigh, which originates from T12. A skin island of up to 15 cm can be harvested and leaves the patient without any functional deficit.
REFERENCE
Smith HO, Genesen MC, Runowicz CD, et al. The rectus abdominis myocutaneous flap: Modifications, complications, and sexual function. Cancer. 1998;83(3):510–520.
MYOFASCIAL PAIN, UROLOGIC CONSIDERATIONS
DESCRIPTION Myofascial sources of pain have been defined in women with myofascial pelvic pain syndrome (MPPS) (see below) and new evidence is mounting that myofascial pain may be a contributing factor in a constellation of chronic male pelvic pain syndromes previously diagnosed as prostatitis or orchitis. Trigger points, defined as hyperirritable, sensitive, or tender spots usually associated with a taut band of skelet al muscle or fascia, have been identified in women with MPPS. A recent study has identified several reproducible trigger points in males with chronic pelvic pain (CPP) on external and internal pelvic exam and an initial investigation has shown improved response to internal and external myofascial physical therapy compared to external massage (57–28%).
REFERENCE
Anderson RU, Sawyer T, Wise D, et al. Painful myofascial trigger points and pain sites in men with chronic prostatitis/chronic pelvic pain syndrome. J Urol. 2009;182:2753–2758.
MYOFASCIAL PELVIC PAIN SYNDROME (MPPS)
DESCRIPTION MPPS is a disorder in which pelvic pain is attributed to short, tight, tender pelvic floor muscles, usually with hypersensitive trigger points. Pelvic floor trigger points refer pain to the vagina, vulva, perineum, rectum, and bladder. Pain can be also be referred to the thighs, buttocks, or lower abdomen. Irritative symptoms (eg, urinary urgency, vulvovaginal burning, rectal fullness) may be more prominent than pain. The diagnosis is clinical. Treatment is customized and based on reducing the response of the trigger point. Stress reduction (meditation, relaxation exercises), physical therapy (stretch/massage), heat, ice, or NSAIDs are recommended for mild cases. Pelvic floor physical therapy (manual myofascial release, stretching, and strengthening) is useful for many patients. More severe cases may require trigger point injections (bupivacaine), gabapentin, or botulinum toxin if muscle spasm can be identified. (See also Section I: “Pelvic Pain, Female.”)
REFERENCE
Srinivasan AK, Kaye JD, Moldwin R. Myofascial dysfunction associated with chronic pelvic floor pain: Management strategies. Curr Pain Headache Rep. 2007;11(5):359–364.
MYOGLOBIN NEPHROTOXICITY
DESCRIPTION Renal failure associated with the excessive deposit of myoglobin into the serum following massive muscle necrosis/rhabdomyolysis. Renal failure is initiated by acute tubular obstruction, and necrosis is caused by free chelatable iron and ischemia. Granular casts are found in the urine. Renal failure is initially manifested by oliguria and followed later by a polyuric state. (See also Section II: “Myoglobinuria and Rhabdomyolysis.”)
TREATMENT
• Myoglobin nephrotoxicity is prevented by maintaining fluid balance through the use of diuretics and hydration, using isotonic saline initially.
• If renal failure develops, fluid retention should be avoided by limiting infusion rates.
• In polyuric states, vigilant replacement of electrolytes is required.
REFERENCE
Melli G, Chaudhry V, Cornblath DR. Rhabdomyolysis: An evaluation of 475 hospitalized patients. Medicine (Baltimore). 2005;84(6):377–385.
MYOGLOBINURIA
DESCRIPTION 1st described by Fleischer in 1881, myoglobinuria refers to the presence of excessive amounts of myoglobin, a protein found in muscle, in the urine. Myoglobinuria occurs when serum levels exceed the renal threshold. Myoglobin is released into the serum following massive muscle necrosis (rhabdomyolysis) from crush, compartment syndrome, electrical injury, toxins, malignant hyperthermia, and other causes, and imparts a cola-like color to the urine. Diagnosis is made by electrophoresis separation and radioimmunoassay of urinary myoglobin. Serum creatinine kinase is elevated, and there is an absence of red cells in the urine. (See also Section I: “Rhabdomyolysis”; Section II: “Myoglobin Nephrotoxicity.”)
CAUSES
• Diabetic acidosis
• Fluid/electrolyte imbalance
• Infectious myositis
• Ischemia
• Malignant hyperthermia
• Neuroleptic malignant syndrome
• Rhabdomyolysis or compartment syndrome
• Toxins
• Trauma
TREATMENT
• Remove the causative agent.
• Protect against renal failure through correction of electrolyte imbalances, alkalinization of urine with sodium bicarbonate, hydration, and diuretics.
REFERENCE
Melli G, Chaudhry V, Cornblath DR. Rhabdomyolysis: An evaluation of 475 hospitalized patients. Medicine (Baltimore). 2005;84(6):377–385.