Brian M. Benway, MD
Gerald L. Andriole, MD, FACS
BASICS
DESCRIPTION
• Urologic masses are usually retroperitoneal in adults
– May arise from several sites
Renal (malignant and benign)
Adrenal
Germ cell (retroperitoneal lymphadenopathy)
Metastatic
Other (retroperitoneal fibrosis [RPF], hematoma, abscess, lymphocele, lymphoma, urinary retention)
EPIDEMIOLOGY
Incidence
• Renal cell carcinoma: 55,000 new cases per year. Incidence is rising (1)
• Testis cancer: 8,000 new cases per year
Prevalence
Varies with disease type
RISK FACTORS
• Cancer (renal, adrenal, testis)
• Prior surgery (lymphocele)
• Infection (abscess, RPF)
• Trauma (hematoma, urinoma)
• Urinary retention
Genetics
• Renal lesions have some known genetic alterations:
– von Hipple Lindau (VHL)
– Hereditary papillary renal cell
– Birt–Hogg–Dubé
– Hereditary leiomyomatosis
– Tuberous sclerosis
PATHOPHYSIOLOGY
• Various urologic pathologic conditions may present with a mass:
• Primary renal neoplasms:
– Malignant: Renal cell carcinoma (RCC), renal sarcoma, adult Wilms tumor, urothelial carcinoma, lymphoma
– Benign: Renal cortical adenoma, renal oncocytoma, renal hamartoma (angiomyolipoma) fibroma
• Primary adrenal neoplasms: Adrenal cortical carcinoma, pheochromocytoma, adrenal adenoma, paraganglioma
• Hydronephrosis
• Primary and metastatic germ cell tumor (GCT): Are composed of seminoma, embryonal cell carcinoma, yolk sac tumor, teratoma, and choriocarcinoma
• Primary extragonadal GCTs can occur intraperitoneally
– Metastatic GCTs are associated with retroperitoneal lymphadenopathy
• Renal abscesses: Usually follow insufficient treatment of lobar nephronia; needle aspiration may be needed to make a diagnosis
• TB can cause cold abscess formation. Pus developing from a renal source may track alongside psoas muscle and appears in the groin, where it must be distinguished from hernia.
• Perinephric abscess: Usually arises as a result of pre-existing renal factors such as renal calculi, ureteral calculi, hydronephrotic changes, renal cystic disease, or infected carcinoma
• Hematomas: May be caused by a ruptured kidney or ureteral avulsion. Blood in the retroperitoneal space may track to the corresponding iliac fossa
• Renal cysts
• Bladder-related: Retention, tumors and urachal abnormality, or cancer
• Metastatic tumors to the adrenal glands and kidney
ASSOCIATED CONDITIONS
• Hydronephrosis, renal insufficiency (malignant obstruction)
• Aortitis, aortic aneurysm (RPF)
• Stauffer syndrome (RCC)
GENERAL PREVENTION
N/A
DIAGNOSIS
HISTORY
• Weight loss, cachexia, night sweats (malignancy or chronic septic disease)
• Spiking fevers, flank pain (infectious)
• Recent trauma with or without hematuria
• History of testis mass
• Classic triad for renal cell carcinoma (hematuria, flank pain, palpable mass) is relatively uncommon in modern era
PHYSICAL EXAM
• Abdominal wall masses such as lipomas, hematomas, lymph nodes, and hernias can be readily determined by physical exam
• Palpable abdominal mass
– Location, tenderness
• Any mucoid drainage from the umbilicus
• Hypertension
• Lymphadenopathy
• Lower extremity edema
• Lower extremity pulses
• Varicocele (more common on right)
– Left side consider renal mass with occlusion of renal vein
• Scrotal exam
DIAGNOSTIC TESTS & INTERPRETATION
Lab
• CBC, complete metabolic panel
• Urinalysis and culture
• Adrenal metabolic workup if adrenal mass is suspected – see Section I “Adrenal Adenoma”
• Tumor markers
– Testis – AFP, β-HCG, LDH
AFP – may be elevated in embryonal, teratocarcinoma, yolk sac, but never in pure choriocarcinoma or pure seminoma
LDH may indicate retroperitoneal involvement, but not specific to testis
• Pregnancy testing where appropriate
Imaging
• Ultrasound
– Good for detecting cystic lesions, but not optimum for calcified masses or smaller stones. Quality is operator-dependent.
• Computed tomography (CT)
– Good for detecting solid abdominal masses, metastatic lesions, and stone.
– CT angiography can evaluate renal vasculature.
– PET-CT approved for diagnosis of RCC metastases.
• Magnetic resonance imaging (MRI)
– Good for evaluating adrenal masses and indeterminate renal lesions.
– Can be used in patients with iodine allergies and renal insufficiency, though caution should be exercised in the latter.
• 131l-metaiodobenzylguanidine (MIBG)
– Only role for evaluating pheochromocytoma.
• Intravenous pyelogram/excretory urogram
– Largely historical, replaced by CT or MR urography.
Diagnostic Procedures/Surgery
• Fine-needle aspiration or core biopsy of mass
– Renal biopsy sensitivity enhanced by use of coaxial core biopsy techniques (2)
Pathologic Findings
Varies depending upon type and location of mass
DIFFERENTIAL DIAGNOSIS
• Adrenal mass: See Section I “Adrenal Mass”
• Distended bladder
• GI tract:
– Hepatomegaly, splenomegaly, pancreatitis, pancreatic mass, tumors, volvulus, constipation
• Gynecologic:
– Pregnancy, uterine fibroids, ovarian cysts, malignancy
– Hydronephrosis
• Other: Intra-abdominal abscess, ascites
• Renal mass: See Section I “Renal Mass”
• Retroperitoneal mass: See Section I ”Retroperitoneal Masses, Fluid, and Cysts”
• Ruptured abdominal aortic aneurysm
• Urachal abnormality
TREATMENT
GENERAL MEASURES
• Varies by underlying ailment
– Renal malignancy – radical or partial nephrectomy, ablation, observation (3)
– Adrenal malignancy – adrenalectomy
– Adrenal adenoma – excision or observation
– Testis cancer – retroperitoneal lymph node dissection, chemotherapy, radiation
– Renal abscess, xanthogranulomatous pyelonephritis – antibiotics, drainage, nephrectomy
– Cysts – observation, decortication, drainage and sclerosis
– Retention – placement of Foley catheter
– Hydronephrosis – double-J stent placement or percutaneous nephrostomy tube placement
MEDICATION
First Line
• Antibiotics for abscess or obstruction
• Corticosteroids, tamoxifen for RPF
Second Line
Mycophenolate mofetil, azathioprine for RPF
SURGERY/OTHER PROCEDURES
Depends upon clinical diagnosis
ADDITIONAL TREATMENT
Radiation Therapy
• Limited utility for renal cell carcinoma
• Used for seminomatous germ cell tumors
Additional Therapies
Depends upon clinical diagnosis
Complementary & Alternative Therapies
N/A
ONGOING CARE
PROGNOSIS
Prognosis depends upon clinical diagnosis and staging
COMPLICATIONS
See associated chapters regarding disease-specific interventions
FOLLOW-UP
Patient Monitoring
Depends upon clinical diagnosis and management. See associated chapters regarding specific disease processes.
Patient Resources
N/A
REFERENCES
1. Chow WH, Devesa SS, Warren JL, et al. Rising incidence of renal cell carcinoma in the United States. JAMA. 1999;281:1628–1631.
2. Maturen KE, Nghiem HV, Caoili EM. Renal mass core biopsy: Accuracy and impact on clinical management. AJR AM J Roentgenol. 2007;188:563–570.
3. Kunkle DA, Kutikov A, Uzzo RG. Management of small renal masses. Semin Ultrasound CT MR. 2009;30:352–358.
ADDITIONAL READING
• Glockner JF, Vrtiska TJ. Renal MR and CT angiography: Current concepts. Abdom Imaging. 2007;32:407–420.
• Hussain HK, Korobkin M. MR imaging of the adrenal glands. Magn Reson Imaging Clin N Am. 2004;12:515–544, vii.
• Johns Putra L, Lawrentschuk N, Ballok Z. et al. 18F-fluorodeoxyglucose positron emission tomography in evaluation of germ cell tumor after chemotherapy. Urology. 2004;64:1202–1207.
• Schoder H, Larson SM. Positron emission tomography for prostate, bladder, and renal cancer. Semin Nucl Med. 2004;34:274–292.
See Also (Topic, Algorithm, Media)
• Abdominal Mass, Adult, Urologic Considerations Image 
• Abdominal Mass, Newborn, Child, Urologic Considerations
• Hydronephrosis
• Renal Masses
• Renal Cell Carcinoma
• Retroperitoneal Masses, Fluid, and Cysts
• Retroperitoneal Fibrosis
• Testis Cancer
CODES
ICD9
• 189.0 Malignant neoplasm of kidney, except pelvis
• 194.0 Malignant neoplasm of adrenal gland
• 789.30 Abdominal or pelvic swelling, mass, or lump, unspecified site
ICD10
• C64.9 Malignant neoplasm of unsp kidney, except renal pelvis
• C74.90 Malignant neoplasm of unsp part of unspecified adrenal gland
• R19.00 Intra-abd and pelvic swelling, mass and lump, unsp site
CLINICAL/SURGICAL PEARLS
• Abdominal masses in the adult can arise from several different processes.
• Radiographic information is often essential to diagnosis.
• Management varies upon disease type.