Primary and metastatic diseases in malignant melanoma of the gastrointestinal tract

In this review, the gastrointestinal (GI) manifestations of malignant melan oma including primary mucosal melanoma of the GI tract and metastatic melan oma to the GI tract are discussed. Although malignant melanoma most commonl y arises in the skin, primary melanomas can also arise from the mucosal epi thelial lining of the gastrointestinal tract. The vast majority of gastroin testinal melanoma is metastatic from a cutaneous primary; however, there is evidence that melanoma can arise de novo from within certain areas of the gastrointestinal system. The sporadic nature and small numbers of patients reported in the literature with mucosal melanomas have prevented a good und erstanding of the pathogenesis, natural history, and optimal treatment of t his uncommon presentation of melanoma. (C) 2000 Lippincott Williams & Wilki ns, inc.