General Surgery (Board Review Series) 1st Edition

21

Skin Cancer and Soft Tissue Sarcomas

Lee W. Thompson

1. Melanoma
2. Etiology and epidemiology
3. Melanocytesoriginate from neural crest cells. Therefore, melanoma can occur anywhere that neural crest cells migrate in the embryo.
4. Melanoma occurs

• primarily in the skin.
• rarely in the eye and mucous membranes(e.g., oral mucosa, anorectum, female genital tract).

3. Melanomas represent

• a minority of skin cancers (3%–5%), but can cause at least 65% of the deaths from skin cancer.

4. The characteristic melanoma patient

• has a fair complexion(i.e., Celtic complexion).
• has a history of sunburning easily.
• may be younger than other patients with skin cancer (80% of melanoma patients are from ages 25–65).

5. A significant risk factor

• for the development of melanoma is intermittent, unaccustomed sun exposure(e.g., sunburns).

6. Other risk factorsand associated conditions include

• sporadic dysplastic nevi(20-fold increase over the general population).

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• familial dysplastic nevi syndrome(B-K mole syndrome, atypical mole syndrome) associated with 100% lifetime risk of melanoma.
• large congenital nevi(larger than 20 cm) have a 5%–20% lifetime risk of melanoma.
• familial predisposition.
• xeroderma pigmentosum.
• previous skin cancer(10-fold increase risk with previous melanoma).

1. The clinical appearance and symptoms

• of melanoma are outlined in Table 21-1.

1. The four main pathologic types of melanoma

• are outlined in Table 21-2.

Table 21-1. Important Factors in the Evaluation of a Skin Lesion

Asymmetry Irregular elevations Any nodular area, indentation, or nonuniformity in elevation should raise the suspicion of a melanoma. Borders Irregular borders More likely melanoma: borders that blend, are difficult to see, and are nondiscrete More likely benign: smooth, discrete, uniform borders Color Variation in color The variation in color across a lesion is more worrisome than any particular color in a uniform lesion. Degeneration Ulceration, itching, bleeding, or rapid changes Worrisome symptoms for melanoma

1. Prognostic factors
2. The depth of invasion

• is an important prognostic indicator for melanoma.
• Two classification systemsare used to describe the depth of invasion of the tumor: Clark's level of invasion (Table 21-3) and Breslow thickness (Table 21-4).

2. Nodal status

• also correlates with prognosis.
• With 1–2 positive nodes, 5-year survival is 30%–55%.

3. Distant metastasis

• is associated with a very poor survival.

4. Other factors associatedwith a relatively poor prognosis
5. Location:posterior neck, scalp, upper back > trunk > hands and feet, listed from worse to better prognosis.
6. Menhave a worse prognosis than do women.
7. Ulcerated lesionshave a worse prognosis than nonulcerated lesions.

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1. Vertical growth characteristicshave a worse prognosis than radial growth characteristics.
2. Ocularand mucosal melanomas are more aggressive than cutaneous lesions.

Table 21-2. Pathologic Classification of Malignant Melanomas

Type Epidemiology Common Site Metastatic Potential Superficial spreading (70%) Equally common among men and women; median age 50 Sun-exposed areas Intermediate aggressiveness Nodular (15%–30%) More common in men; peaks in the 5th decade Sun-exposed areas; may occur in normal skin without pre-existing nevi Most aggressive form Lentigo maligna melanoma (10%–15%) More common in women; median age 70 Sun-exposed areas (head, neck, and dorsum of the hand); frequently arises at site of Hutchinson freckle (benign, brown, macular lesion) Least aggressive Acral lentiginous (rare) Uncommon except in dark-skinned people; median age 60 Occurs on the palms, soles, and subungual regions; more than 75% involve large toe or thumb Intermediate aggressiveness

Table 21-3. Clark's Level Classification System for Melanoma

Clark's Level* Definition I All tumor cells confined to the epidermis with no invasion through the basement membrane (melanoma in situ) II Tumor cells penetrate through basement membrane into the papillary dermis, but not to the reticular dermis III Tumor cells fill the papillary dermis and abut the reticular dermis but do not invade it IV Tumor invades reticular dermis V Tumor cells invade the subcutaneous tissue *For staging purposes, the Breslow thickness has largely replaced Clark's levels for characterization of primary lesion (see Table 21-4).

1. Evaluation
2. Biopsy of suspected melanoma

• must include the full depthof the lesion to evaluate tumor thickness.

2. Total excisional biopsy

• should be attempted for small lesions.

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3. Physical examination

• of all possible draining lymph nodes should be performed.

4. Although not routine, other testscan be used during evaluation.

• A chest radiographmay identify lung metastasis.
• Lactate dehydrogenaseand alkaline phosphatase may be measured to screen for hepatic metastasis.
• Recently, lymphoscintigraphyhas been used to identify the “sentinel lymph node” (see I F 3 a).

Table 21-4. Breslow Classification System and Staging of Melanoma

1. Treatment

Table 21-5. Recommended Margin of Resection for Wide Local Excision of Melanoma

Depth of Melanoma Recommendation for Margins Melanoma in-situ 0.5 cm ≤1 mm thick 1 cm 1 mm to 4 mm thick 2 cm >4 mm thick 3 cm

1. With all stagesof melanoma

• the primary lesion is treated with wide local excision.
• The size of the margingenerally depends on the depth of invasion (Table 21-5).
• The lesion site, such as on the head and neck, may influence margin size.

2. Most patients with stage I disease

• will be cured by resection alone.

3. Stage IIA and IIB melanomas

• (based on depth of invasion) are also treated with wide local excision of the primary lesion.

1. Cutaneous areasusually drain first to a single or small group of lymph nodes known as the sentinel lymph node.

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1. Some surgeons currently recommendperforming a sentinel lymph node biopsy at the time of initial resection.
2. If the sentinel lymph node does not have melanoma then the other lymph nodes are unlikely to be positive(98% sensitivity).
3. Patients with stage III tumors

• in addition to wide local excision, should also undergo full lymph node dissectionof the affected lymph node group.

1. Five-year survivalwith resected positive nodes is 30%–50%.
2. Postoperatively, some high-risk patients receive interferon-α.
3. Other types of immunotherapy and chemotherapy are currently being evaluated.
4. Resection of metastasis (Stage IV)

• is warranted for palliation of symptoms.

1. For some patients, resection of metastasishas provided long disease-free intervals.
2. In eligible patients, resection of single lesions(e.g., lung) that will require a relatively low-risk procedure remains the best chance for cure and long-term survival.
3. Melanoma may rarely metastasizeto the gastrointestinal tract.

• This causes obstruction or bleeding, which may require resection of the affected bowel.

6. Other therapies

. Interleukin-2 therapy has a significant response rate in patients with advanced disease.

1. Chemotherapeutic agentshave generally not been shown to provide benefit in the treatment of melanoma.
2. Tumor vaccine therapyand other types of immunotherapy are currently being investigated.
3. Nonmelanoma Skin Cancer
4. Etiology and epidemiology
5. Skin cancer

• is the most common malignancy in the United States.
• is 70 times less likely to develop in African Americans.

2. Basal celland squamous cell carcinomas

• make up the vast majority of nonmelanoma skin cancers.

3. Basal cell cancers occur

• 3–4 times more frequently than squamous cell cancers.

4. Basal celland especially squamous cell cancers

• are related directly to chronic sun exposure.
• occur most commonly on areas of the body that receive chronic sun exposure.

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5. Patients who develop a skin cancer

• have a 36%–50% chance of developing a second primary skin cancer in the 5 years following the original diagnosis.

1. Overall risk factors include

• fair skin, red or blonde hair, blue eyes.
• Celtic origin.
• immunosuppression(e.g., transplant patient).
• exposure to ultraviolet (UV) light(especially UVB).
• exposure to ionizing radiation.
• chemical exposure(polycyclic aromatic hydrocarbons, e.g., coal tar; chlorophenols; arsenic; psoralen).
• precursor skin lesions(e.g., actinic keratosis, Bowen's disease).

1. The differential diagnoses of a skin lesion may include, in addition to malignant skin lesions, these benign conditions:

• actinic keratoses.
• keratoacanthoma.
• warts.
• acneform papules.
• eczema.
• chalazia.
• seborrheic keratoses.

1. Squamous cell carcinoma (cutaneous)
2. Specific risk factorsinclude

• human papillomavirus.
• immunosuppression.
• old scars and burns(Marjolin's ulcer is a squamous cell carcinoma that develops at the site of an old scar or burn).
• sinus tracts.
• venous stasis ulcers.
• tobacco use, which is a significant risk factor for mucosal squamous cell carcinomas (i.e., lip, gums).

2. Precursor lesionsinclude

• actinic keratosis.
• Bowen's disease.
• Queyrat erythroplasia.

3. Appearance
4. Lesions are usually red to reddish brown, but may be pearly.

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1. The surface may be crusted, scaly, or hyperkeratotic with erosions and ulcers.
2. These lesions are typically painless and have poorly defined bordersand develop over a period of weeks to 2–3 months.
3. Metastasis

. Squamous cell cancers metastasize

• more frequently than basal cell cancers but much less frequently than melanomas.

1. Factors predictive of metastasisinclude

• degree of differentiation(grade).
• depth of penetration and size.
• location of lesion(lip and ear have highest risk).
• recurrent lesions(25%–45% rate of metastasis).
• age.
• immune status of patient.

1. Basal cell carcinoma
2. These carcinomas

• are slow-growing.
• are locally destructive malignancies.
• have an extremely low incidence of metastasis.

2. Incidence is related to total sun exposure

• however, basal cell cancer appears to be related more to irregular sun exposurethan to persistent sun exposure.
• More than 80%of basal cell cancers are found on the head and neck, with the nose as the most common site.

3. Genetic alterations

• that are known to be caused by UV light are common in basal cell cancer cells.

4. Subtypesof basal cell cancer
5. Nodular:pearly translucent nodule often with central ulceration (rodent ulcer).
6. Micronodular:group of small, nodular lesions.
7. Superficial:flat, scaly, eczema-like lesion.

• Tumor often extends beyond the clinically positive border.

1. Infiltrative:lesions are often difficult to see because they blend with the skin.
2. Morpheaform:flat, firm, yellow-to-tan lesion that often extends well beyond the clinically positive borders.
3. Mixed:composed of more than one of the above tumor elements.
4. Basosquamous cell carcinoma:separate foci and components of both basal cell and squamous cell tumors.
5. Treatment
6. Wide local excision

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• of lesions with negative margins is associated with a 95%–99% cure rate.

1. Margins of 5 mm are acceptable for most lesionsalthough some complex lesions may require 10 mm margins.
2. Recurrent basal cell cancersshould be treated aggressively because the rate of re-recurrence is high.
3. Mohs' micrographic technique

. Lesions are removed with what is thought to be a 2–3 mm margin.

1. The excision is continued until the margins are freeof microscopic disease.

• Therefore the procedure has theoretically 100% margin control.

1. This technique is designedto provide adequate resection of lesions with sparing of normal tissue (i.e., face lesions).
2. This method is contraindicated if a melanoma is suspected.
3. Other proceduresused for treating small lesions include

• curettage and electrodesiccation.
• cryosurgery.
• CO₂or neodymium laser.
• topical 5-fluorouracil.
• topical or oral retinoids.
• intralesional interferon-α_2b.

4. Systemic chemotherapy

• is reserved for tumors that are inoperable or metastatic.

5. Radiation therapy

• is generally reserved for inoperable lesions.

6. Although rare, lymph node metastasis

• can be treated with lymph node dissection or possibly radiation therapy.

III. Soft Tissue Sarcomas

1. Introduction and epidemiology
2. Most sarcomas arisefrom tissues that developed from embryonic mesoderm.
3. Because of their origin, soft tissue sarcomas can arise anywhere in the body.
4. Approximately 50% arise in the extremities.
5. Half of all sarcomas occur in children.
6. When these lesions metastasize, spread is almost uniformly by hematogenous route.
7. Lymph node involvement is uncommon.
8. Risk factors

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1. Radiation exposure

• A 7–20 year latency period is generally present for radiation-induced sarcomas.

2. Thorotrast

• is associated with angiosarcoma of the liver 18–36 years later.
• was once used as a contrast medium, but is no longer available.

3. Chemical exposuresinclude

• phenoxyacetic acids (herbicides).
• chlorophenols.
• vinyl chloride.
• arsenic.

4. Chronic lymphedema

• Stewart-Treves syndrome is the classic lymphangiosarcomain postmastectomy, postirradiated patients with a lymphadenomatous arm after breast cancer treatment.
• The lymphangiosarcomas occur outside the irradiated field.

5. Genetic syndromes

• associated with sarcoma development are listed in Table 21-6.

Table 21-6. Familial Syndromes Associated with the Development of Sarcomas

Syndrome Tumor Types Neurofibromatosis Benign or malignant central nervous system tumor; malignant peripheral nerve sheath tumor; pheochromocytoma Li-Fraumeni cancer syndrome Childhood rhabdomyosarcoma, as well as many other tumors later in life including sarcomas Hereditary retinoblastoma Retinoblastoma, as well as many other tumors later in life including sarcomas Tuberous sclerosis Angiomyolipoma Gardner's syndrome Familial adenomatous polyposis and multiple intra-abdominal desmoid tumors

1. Diagnosis
2. Most sarcomasare large (larger than 5 cm), grow rapidly, and are painless.
3. Patients may wrongly associate these lesionswith trauma, thus delaying consultation with a physician.
4. Presenting signsof a visceral or retroperitoneal sarcoma include

• asymptomatic abdominal mass (most common presentation).
• gastrointestinal bleeding.
• bowel obstruction.
• neurologic deficits.

4. The ratio of benign to malignant tumors is greater than 100 to 1.

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5. Most sarcomas present as a soft tissue mass that must be differentiated from

• reactive processes.
• benign tumors.
• calcified post-traumatic muscle masses (myositis ossificans).
• metastatic carcinomas.
• melanoma.
• lymphoma.

6. Indications for biopsyof soft tissue masses include

• symptomatic lesions.
• enlarging lesions.
• lesions larger than or equal to 5 cm.
• new masses that persist for longer than 5 weeks.

1. Prognosis and staging
2. The histologic grade of the primary tumor

• is the predominant factor in predicting metastatic recurrence and mortality.

2. Factors used to establish tumor gradeinclude

• cellularity.
• differentiation.
• pleomorphism.
• necrosis.
• number of mitoses.

3. Tumors larger than or equal to 5 cm

• are more likely to metastasize.
• are associated with a higher mortality.

4. Overall morbidity and mortality

• may also be related to the site of the primary lesion and its resectability.

5. A summary of sarcoma stagingbased on tumor grade and size is outlined in Table 21-7.
6. The risk of recurrenceremains significant after 5 years without disease.

• Factors associated with recurrence and disease specific mortality are included in Table 21-8.

1. Diagnosis and treatment of site-specific sarcomas
2. Sarcomas of the extremities
3. A chest radiograph

• is essential because 88% of metastases from extremity lesions are to the lung.

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Table 21-7 Staging System for Sarcomas

Stage Grade Size Metastasis IA Low <5 cm No IB Low >5 cm No IIA Moderate <5 cm No IIB Moderate >5 cm No IIIA High <5 cm No IIIB High >5 cm No IVA Any Any Lymph nodes only IVB Any Any Distant

1. Computed tomography (CT) or magnetic resonance imaging (MRI) scans

• are frequently useful for operative planning and for identifying metastasis.

1. Biopsy of the lesion
2. Three methodsmost commonly used to obtain biopsy material include

• excisional biopsy.
• incisional biopsy (preferred in most situations).
• Tru-cut needle biopsy.

2. The biopsy is performed so that the biopsy incision can be included in the definitive sarcoma resection.
3. Meticulous hemostasis must be maintained because the hematoma can disseminate and assist spread of tumor cells.

Table 21-8. Factors Associated with Increased Recurrence Rates and Mortality in Sarcomas

Increased Local Recurrence Increased Distant Recurrence Increased Disease-Specific Mortality Age >50 years Lesions ≥ 5 cm Large tumor size Positive primary margins High grade lesions High grade lesions Histologic subtypes (e.g., peripheral nerve tumors) Deep location of tumor Histologic subtypes (e.g., leiomyosarcoma > liposarcoma) Deep location of tumor Treatment of recurrent disease Positive primary margins Lower extremity tumors Histologic subtypes (e.g., leiomyosarcomas and peripheral nerve tumors)

1. Treatment of sarcomas smaller than 5 cm

• is via wide en bloc surgical resectionwith 2–4 cm wide tumor-free margins.
• Limb-sparing procedures should be performedwith amputation reserved for situations when no other option exists.
• Radiation therapy should be combined with surgery if the tumor margins are of concern.

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1. Treatment of extremity sarcomas larger than 5 cm
2. Limb sparing surgery combined with adjunctive radiation therapyis the treatment of choice.
3. Although a group of these patients will have local recurrences that require further resection and treatment, long-term survival is not affected.
4. Patients with tumors larger than 10 cm

• are usually good candidates for preoperative or neoadjuvant radiation therapy.

1. Chemotherapy does notcurrently

• play a significant role in the treatment of soft tissue sarcomas.

2. Visceral or retroperitoneal sarcoma
3. A CT or MRI scanof the abdomen and pelvis allows for assessment of the primary lesion and metastatic disease.
4. A chest radiographto identify metastasis is essential.
5. The predominant lesions identifiedare leiomyosarcoma and liposarcoma.
6. Surgical resectionis the mainstay of treatment for these sarcomas.
7. Tumors are usually very large at the time of diagnosis.
8. Resection of adjacent organs is routine, although the impact on long-term survival is limited.
9. The ability to completely resect the primary tumor is the most important prognostic factor.
10. Incomplete resections do not improve long-term survival.
11. Unresectabilityis usually related to peritoneal implants or extensive vascular involvement.
12. The incidence of local recurrence is high, although many recurrences can be re-resected.
13. Head and neck sarcomas
14. Many of the head and neck sarcomasoccur in the pediatric population.

• Rhabdomyosarcomais the most common.

1. Even for small lesionstumor-free margins are difficult to obtain owing to the close proximity of vital structures.
2. Postoperative radiation therapyis a very important part of local control because adequate margins are often difficult to obtain.
3. Sarcoma of the breast

• accounts for fewer than 1% of all breast tumors.

1. These lesions rarely metastasizeto the lymph nodes, unlike breast carcinoma.
2. Treatmentinvolves en bloc resection with wide margins, as in other parts of the body.

• Lymph node dissection is not routinely performed, unlike in carcinoma of the breast.

1. Treatment of local recurrence
2. If complete resection can be accomplished then the recurrence should be resected.

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2. Re-irradiationcombined with resection of the recurrence has been shown to decrease local recurrence rates in certain patient populations.
3. Metastatic sarcoma
4. Overall, 20% of patientswith sarcoma present with distant metastasis.
5. Palliative resection of symptomatic lesions and radiation therapy are used on an individual basis.
6. Resection of locally advanced diseaseand metastatic lesions can offer longer disease-free survival, but the risk of the procedure must be weighed against that potential benefit.
7. Resection of isolated pulmonary metastasis may be associated with a 20%–30% increase in the 5-year survival rate.
8. The role of chemotherapyin the treatment of metastatic disease is still being investigated.
9. Kaposi's sarcoma

• is a rare, aggressive sarcoma seen most commonly in severely immunosuppressed patients(e.g., acquired immunodeficiency syndrome [AIDS]).

1. These lesions involvethe skin or mucous membranes and occasionally the intestinal tract.
2. Surgery is indicatedwith intestinal perforation or hemorrhage, although overall survival is very low.
3. Desmoid tumors

• may be considered low-grade sarcomasor a reactive process.

1. When resected, desmoids frequently recur locally but rarely metastasize.
2. Trauma or surgerycommonly precedes the development of desmoids.
3. These lesions are divided into three subgroups.
4. Extra-abdominal desmoids

• tend to occur on the muscles of the back, shoulders, chest wall, and thigh.

1. Abdominal desmoids

• arise in the musculoaponeurotic structures of the anterior abdominal wall.
• classically occur during or following pregnancy.

1. Intra-abdominal desmoids

• are associated with Gardner's syndrome.
• may be associated with diffuse retroperitoneal fibrosis.

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Review Test

Directions: Each of the numbered items or incomplete statements in this section is followed by answers or by completions of the statement. Select the ONE lettered answer or completion that is BEST in each case.

1. A 54-year-old man presents to the office with a complaint of a mass in his left thigh increasing in size over the past several months. On examination, the patient is noted to have a firm 6-cm mass on his left anterior thigh with no other significant findings. An incisional biopsy reveals a soft tissue sarcoma. Which of the following is the most appropriate statement regarding the initial evaluation and management of this patient?

(A) A sentinel lymph node biopsy should be performed because sarcomas spread almost uniformly through lymphatics to lymph nodes

(B) A chest radiograph should be obtained because sarcomas spread almost uniformly by a hematogenous route with a majority going to the lung

(C) Resection alone is the next step because growth is so slow that where it spreads is not a concern

(D) Multiple local skin biopsies should be performed because sarcomas usually spread superficially through the skin

(E) Immediate amputation should be performed because of the aggressive nature of sarcomas occurring in the extremities

1–B. A chest radiograph is essential in the evaluation of patients with sarcomas because the lung is the most common site of metastasis. In contrast, sarcomas rarely metastasize via the lymphatics, and thus biopsy of the sentinel lymph node is not routinely performed. Preoperative evaluation of patients with sarcoma allows for identification of metastatic disease, which occurs frequently with these lesions. Sarcomas preferentially spread via hematogenous routes and rarely spread superficially to the skin. In addition, performing multiple biopsies may increase the likelihood of tumor seeding of the blood and metastasis. Limb-sparing procedures are currently preferred over amputation in the management of most extremity sarcomas.

2. A 66-year-old, diabetic woman underwent a lumpectomy/axillary node dissection with postoperative radiation therapy 17 years ago for breast adenocarcinoma. The patient gives a history of a severe skin “reaction” to the radiation and a history of chronic swelling of the affected arm. She now presents with a mass in the upper portion of the affected extremity, recently diagnosed as a lymphangiosarcoma. Which of the following factors in this patient is thought to be most important in the source of this sarcoma?

(A) History of previous breast malignancy

(B) Chronic lymphedema

(C) History of radiation exposure

(D) Advanced age

(E) History of chronic diabetes

2–B. The pathogenesis of the development of lymphangiosarcomas in these patients is related to the presence of chronic lymphedema. These lesions often occur outside the irradiated field and are not specifically related to the pre-existing breast cancer. Advanced age and a history of diabetes are also not direct risk factors for the development of these lesions. Lymphangiosarcomas may also arise in association with lymphedema caused by filarial infection (elephantiasis) or other chronic lymphedematous states.

3. A 54-year-old construction worker presents to the office for a routine check-up. He is noted to have a 6-mm, dark lesion under the fingernail of a finger on his left hand. He denies any trauma to the area. The area is nontender with no evidence of infection. Which of the following is an appropriate statement regarding the lesion identified in this patient?

(A) This is the most common form of melanoma

(B) This lesion occurs most commonly in white males

(C) This lesion developed from a subungual hematoma

(D) This is the most aggressive form of melanoma

(E) This lesion can also develop on the soles of the feet

3–E. Although overall these lesions are rare, acral lentiginous melanomas generally occur in regions of the body not exposed to the sun, including the palms, soles, and subungual regions. This form of melanoma most commonly occurs in patients with dark skin. Although these tumors are frequently mistaken for traumatic subungual hematomas, these tumors do not develop specifically from these injuries. Melanomas of the digits frequently require amputation for adequate resection. The most aggressive type of melanoma is the nodular variant, not acral lentiginous lesions.

4. Three years ago, a 55-year-old man had a sarcoma resected from his anterior superior thigh that had positive margins on the pathology specimen. He was treated with postoperative radiation therapy to salvage his leg. Unfortunately he developed a recurrent lesion that appears to be 4–5 cm medial to the femoral neurovascular bundle. Which of the following is the most appropriate treatment measure for this patient?

(A) Surgical resection

(B) Doxorubicin and ifosfamide combination

(C) Immunotherapy combined with interferon-α

(D) Observation until lesion becomes symptomatic

(E) Radiation therapy alone

4–A. Surgical re-resection is still the most appropriate treatment strategy even for recurrent lesions. Radiation therapy may play an adjunctive role but is not the best therapy when used alone. Chemotherapy and immunotherapy play little, if any, role in the local treatment of recurrent disease. Observation alone would be inappropriate.

5. A 63-year-old woman presents to the office for a routine check-up. She states that she recently read an article that discussed the different types of skin cancer and that a friend of hers recently had a basal cell cancer removed. She is inquiring about her risk for the development of skin cancer. In describing the risk factors for development of nonmelanoma skin cancers to this patient, which of the following is accurate regarding the relative risks?

(A) Pre-existing keratoacanthoma is a greater risk than pre-existing Bowen's disease

(B) Immunocompetence is a greater risk than immunosuppression

(C) Brown eyes is a greater risk than blue eyes

(D) Brunette hair is a greater risk than blonde hair

(E) Ultraviolet (UV)B exposure is a greater risk than UVA exposure

5–E. Exposure to ultraviolet (UV) light is a risk factor for the development of nonmelanoma skin cancers, although among the different types, UVB light is associated with a greater risk than UVA light. Bowen's disease is a premalignant lesion that predisposes to squamous cell carcinoma, while a keratoacanthoma is a benign lesion. Immunosuppression is also a significant risk factor for skin cancers. Other characteristics that may be associated with a greater risk of skin cancer development include fair skin, blue eyes, and blonde hair. These factors are generally related to the sensitivity of the patient's skin to light exposure.

6. During routine chest radiography, a 63-year-old man is found to have an isolated 1-cm mass in the upper lobe of his right lung. Biopsy of the lesion reveals a melanoma. In addition to examining all skin and mucous membrane surfaces, which of the following would be most appropriate in the subsequent evaluation of this patient to identify the primary lesion?

(A) Funduscopic examination, proctoscopy, and chest computed tomography (CT).

(B) Funduscopic examination and abdominal CT

(C) Chest CT

(D) Chest and abdominal CT

(E) Funduscopic examination and small bowel contrast study

6–A. By far the most common site of melanoma is on the skin surfaces, therefore, all patients should undergo extensive examination of skin surfaces to identify the primary lesion. If a primary skin lesion is not identified, other potential sites for melanoma development include the mucous membranes (e.g., mouth, nasal passages), on the fundus of the eye, and in the anorectal region. Otoscopy is also essential to identify potential lesions within the ear canal. Therefore, a careful funduscopic examination should be performed, in addition to careful evaluation of the anorectum with proctoscopy if necessary. A chest and abdominal computed tomography (CT) and a small bowel contrast study are not routinely indicated in this setting. Approximately 5% of patients will not have an identifiable primary lesion in the setting of metastatic disease.

7. During an abdominal computed tomography (CT) scan performed for complaints of vague abdominal discomfort, a 55-year-old man is found to have a 6-cm mass near the midline in the retroperitoneum suggestive of a sarcoma. Which of the following is an appropriate statement regarding the evaluation and management of this patient?

(A) The presence of multiple peritoneal implants is an appropriate indication for surgical resection of asymptomatic disease

(B) In addition to surgical resection, radiation therapy is a key component of the treatment regimen

(C) Because of the location of this lesion, metastases are more likely found in the liver versus the lung

(D) Given the patient's age and location of the tumor, this lesion is most likely a rhabdomyosarcoma

(E) After initial surgical resection, if the lesion recurs locally, re-resection is appropriate

7–E. Repeat surgical resection is still the most appropriate treatment strategy for locally recurring sarcomas. The presence of peritoneal implants is generally a contraindication to surgical resection of asymptomatic sarcomas. Preoperative assessment may also include angiography to rule out potential vascular invasion, which is another common contraindication to resection of the lesion. Radiation of the retroperitoneum is associated with significant morbidity and does not play a significant role in the treatment of recurrent retroperitoneal sarcomas. Although visceral sarcomas may frequently metastasize to the liver, retroperitoneal sarcomas rarely do; and the lung is generally the most common location of metastatic disease. The most common lesions in this site in patients in this age group are leiomyosarcomas and liposarcomas.

8. A 45-year-old woman presents to the office with complaints of a hard mass in her abdomen. She is otherwise healthy and has 3 children, 1 recently born by cesarean section. Upon examination, the patient is noted to have a firm, 3-cm, subcutaneous mass, inferior to the umbilicus and just lateral to the midline. Excisional biopsy of the lesion reveals a desmoid tumor. Upon discussion of this lesion with the patient during follow-up, which of the following is an appropriate statement regarding the nature of this lesion?

(A) These lesions rarely recur after resection

(B) These lesions may be a high risk for metastasis

(C) These lesions may behave like low-grade sarcomas

(D) These lesions are frequently associated with retroperitoneal fibrosis

(E) Postoperative chemotherapy is a key component of therapy

8–C. Desmoid tumors are soft tissue tumors that can behave like low-grade sarcomas; however, they rarely metastasize. Despite the low frequency of metastasis, these lesions frequently recur locally despite resection. There are 3 subgroups of desmoid tumors and the abdominal wall desmoids frequently occur during or following pregnancy and may be related to previous scars. The intra-abdominal desmoids are associated with Gardner's syndrome and are prone to the development of retroperitoneal fibrosis. The primary treatment is surgical resection, with some lesions responding to radiation therapy. Chemotherapy does not play a significant role in the treatment of these lesions.