anal melanoma

anal melanoma

A variant of melanoma, which comprises up to 1% of anal tumours and 1% of melanomas, but 24% of mucosal melanomas.

Epidemiology
Caucasians; F > M; mean age 60; HIV increases risk.
 
Management
Radical excision; chemotherapy is of uncertain efficacy.

Prognosis
10–30% 5-year survival; > 3-mm thick, 11 months.
References in periodicals archive ?
Second, the anal melanoma is not only an exceptionally rare neoplasm but also particularly an aggressive disease that tends to appear in the elderly population with poor prognosis due to high risk of distant metastases (3).
Anal Melanoma in an Elderly Woman Masquerading as Hemorrhoid.
An interesting case of anal melanoma caused liver metastases due to misdiagnosed as hemorrhoids.
Because of the morbidity related with abdominoperineal resection, wide local surgery procedure is suggested for primary treatment of localized anal melanoma. Sometimes, wide local excision might not be possible and abdominoperineal resection might be necessaried if the tumor wraps a considerable component of the anal sphincter.
The histologic features of anal melanoma resemble those of cutaneous melanomas.
Management of anal melanoma remains a major challenge.
Anal melanomas account for about 4% of anal canal tumors and less than 1% of all melanomas.
(60) Other studies (61,62) have shown that 62% of acral and mucosal melanomas exhibit constitutive KIT receptor activity, and that 15% of anal melanomas harbor activating KIT mutations.
L576P KIT mutation in anal melanomas correlates with KIT protein expression and is sensitive to specific kinase inhibition.
(2) Anal melanomas exhibit the same immunohistochemical and ultrastructural features as their cutaneous counterparts.