Extracutaneous melanoma with special emphasis on mucosal melanoma

Despite the rarity of extracutaneous melanomas they represent a tumor entity with a very high mortality due to delayed diagnosis. This review article presents the various biological and diagnostic characteristics of extracutaneous melanomas with special emphasis on mucosal melanoma and provides an overview of new pharmacological approaches urgently needed due to the lack of efficacious standard therapies. A systematic literature search was conducted by using the English terms extracutaneous melanoma, mucosal melanoma, uveal melanoma, leptomeningeal melanoma and c-KIT in the Medline database between 1982 and 2014. Extracutaneous melanomas comprise approximately 1.4-5 % of all melanomas and are a rare tumor entity. They develop from de-differentiated dendritic melanocytes in the mucus membranes of the gastrointestinal tract, genitourinary tract and respiratory system, in the back of the eyes or the meninges. As they are difficult to detect, extracutaneous melanomas are often already associated with an advanced disease progression at the time of first diagnosis. The class of c-KIT inhibitors has proven to be a new effective targeted therapy for extracutaneous melanomas harboring the appropriate mutational status. Because of the rarity of this tumor entity prospective, randomized control trials are lacking. Therapeutic approaches should, therefore, always be individualized taking into account the special requirements in each case.