Primary noncutaneous melanoma.

Primary noncutaneous melanomas are rare neoplasms that affect patients in an older age group than primary cutaneous melanomas. The prognosis is worse than primary cutaneous melanomas because of the advanced stage at the time of diagnosis, the rich vascular and lymphatic supply of mucosal sites, and the lack of clinical suspicion of the tumor because of its rarity. The initial treatment is surgical resection but the location may make it technically difficult to obtain complete tumor removal. Unlike cutaneous melanoma, sun exposure is not a risk factor for noncutaneous melanomas. Darker-skinned individuals may have a higher incidence of some noncutaneous melanomas, such as anorectal melanomas. It is important for clinicians and pathologists to recognize primary noncutaneous melanomas to provide early detection and optimum management.