In-Service Exam
Melanoma - 2003





PHOTO

A 68-year-old man has the lesion shown in the photographs above. A satellite lesion is noted 2 cm from the primary lesion. Findings on laboratory studies and radiographs of the chest are normal. Histologic examination of a biopsy specimen of the primary tumor shows findings consistent with Clark's level IV melanoma. The tumor has a Breslow's thickness of 2.8 mm. There is no palpable adenopathy or distant metastases.

According to the American Joint Committee on Cancer, which of the following is the correct clinical classification stage of this tumor?

(A) Stage 0
(B) Stage I
(C) Stage II
(D) Stage III
(E) Stage IV

The correct response is Option D.

The staging of melanomas involves three descriptors: T, N, and M. The T descriptor is based on the diameter or surface area of the tumor. The N descriptor describes nodal status. The M descriptor indicates distance of metastasis beyond the neck. This staging criteria allows physicians to predict patient outcomes and choose appropriate therapy based on comparisons with patients in large studies.

This patient's tumor is classified as T4 N0 M0, or Stage III. Although earlier staging classifications placed patients with T4 tumors into a stage IIB subgroup, this has recently been changed by the American Joint Committee on Cancer because of the more aggressive behavior of melanoma and the similarity of disease outcome to other Stage III tumors.

Breslow's thickness typically takes precedence over Clark's level in the classification of melanoma; however, because this patient has a satellite lesion, which represents a more advanced level of disease, the tumor is classified as T4. Satellite lesions, defined as those lesions located within 2 cm of the primary tumor, affect tumor classification. In contrast, secondary lesions farther than 2 cm from the primary tumor are considered in-transit metastases, which influence nodal classification. The patient has not been shown to have palpable nodes or distant organ metastases; therefore, the tumor is classified as N0 and M0 respectively.

A TNM classification table is shown below.

Status of Tumor (T)
TX - Primary tumor cannot be assessed
T0 - No evidence of primary tumor
Tis - Carcinoma in situ
T1 - Tumor 2 cm or less in greatest dimension
T2 - Tumor more than 2 cm but not more than 4 cm in greatest dimension
T3 - Tumor more than 4 cm in greatest dimension
T4 - (lip) Tumor invades adjacent structures (eg, through cortical bone, inferior alveolar nerve, floor of mouth, skin of face)
T4 - (oral cavity) Tumor invades adjacent structures (eg, through cortical bone, into deep [extrinsic] muscle of tongue, maxillary sinus, skin. Superficial erosion alone of bone/tooth socket by gingival primary tumor is not sufficient to classify as T4).

Stages of Lymph Nodes (N)
NX - Regional lymph nodes cannot be assessed
N0 - No regional lymph node metastasis
N1 - Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension
N2 - Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension; or in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimensions; or in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension
N2a - Metastasis in a single ipsilateral lymph node more than 3 cm but not more than 6 cm in greatest dimension
N2b - Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension
N2c - Metastasis in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension

Status of Metastasis (M)
MX - Distant metastasis cannot be assessed
M0 - No distant metastasis
M1 - Distant metastasis

References
1. Fleming ID, Cooper JS, Henson DE, et al. AJCC Cancer Staging Manual. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:163-170.
2. Medina JE, Canfield V. Malignant melanoma of the head and neck. In: Myers EN, Suen JY, eds. Cancer of the Head and Neck. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1996:160-183.

Which of the following is associated with invasive malignant melanoma?

(A) Actinic keratosis
(B) Bazex syndrome
(C) Erythroplasia of Queyrat
(D) Nevus sebaceus of Jadassohn
(E) Xeroderma pigmentosum

The correct response is Option E.

Although all of the lesions listed are premalignant, only xeroderma pigmentosum is likely to develop into invasive malignant melanoma. In patients who have this autosomal recessive condition, the skin is intolerant to ultraviolet light. Pigmentary changes result from absence of DNA repair mechanisms; affected patients develop freckling and thickening of the skin, with atrophy of the subcutaneous tissues. Malignant tumors, including melanoma, frequently develop in patients younger than 10 years. Appropriate management includes minimal sun exposure and topical sun protection.

Actinic keratoses are common premalignant lesions that occur following excessive exposure to sunlight. These lesions appear flesh colored to brown and are rough and scaly with discrete erythematous borders. If untreated, 10% of patients will develop squamous cell carcinoma. Topical application of 5-fluorouracil or surgical excision is appropriate.

Bazex syndrome is an X-linked, autosomal dominant condition that manifests as follicular atrophoderma with multiple basal cell carcinomas. Hypotrichosis and hypohidrosis are associated.

Erythroplasia of Queyrat is also known as Bowen's disease of the mucous membranes, or squamous cell carcinoma in situ. These bright red, velvety lesions affect the glans penis and prepuce, and occur less often on the vulva. Conservative excision is recommended.

Nevus sebaceus of Jadassohn is a lesion affecting the head and neck region that is present at birth and enlarges gradually. Because 10% to 15% of patients with this condition will eventually develop basal cell carcinoma, excision should be performed before the patient reaches puberty. Malignant adnexal tumors such as apocrine carcinoma occur infrequently.

References
1. Netscher D, Spira M, Cohen V. Benign and premalignant skin conditions. In: Achauer BM, Erikson E, Guyuron B, et al, eds. Plastic Surgery: Indications, Operations, and Outcomes. Saint Louis, Mo: Mosby Ð Year Book, Inc; 2000;1:293-324.
2. Preston DS, Stern RS. Nonmelanoma cancers of the skin. N Eng J Med. 1992;327:1649-1662.

An 18-month-old boy has a 25-cm pigmented lesion on his back. Which of the following is the most appropriate management?

(A) Observation with photographic mapping
(B) Intralesional injection of interferon gamma
(C) Dermabrasion
(D) Tunable dye laser ablation
(E) Excision

The correct response is Option E.

This 18-month-old boy has a giant congenital nevus on the back. Congenital nevi can be classified as "giant" according to several criteria, including those lesions that are larger than 20 cm in diameter, lesions that are greater than twice the size of the patient's palm, and those nevi for which excision and primary closure cannot be performed as a single procedure. Because of the potential for malignant transformation, surgical excision of the entire lesion is recommended. Although the actual risk for melanoma is controversial, one study reported that approximately 8% of patients with giant congenital nevi developed melanoma during the first 15 years after the initial appearance of the nevus.

Although observation with serial photographic mapping is advocated in patients with familial dysplastic nevus syndrome, it is not appropriate in a patient with a giant congenital nevus because of the association with malignancy. Intralesional injection of interferon gamma is indicated for patients who have confirmed malignant melanoma. Dermabrasion and laser ablation will not remove all of the immature melanocytes within the lesion. In addition, the resultant hypopigmentation seen following treatment may hinder any future monitoring for signs of malignant degeneration.

References
1. Casson P, Colen S. Dysplastic and congenital nevi. Clin Plast Surg. 1993;20:105-111.
2. Gosain AK, Santoro TD, Larson DL, et al. Giant congenital nevi: a 20-year experience and an algorithm for their management. Plast Reconstr Surg. 2001;108:622-631.