Late recurrence of malignant melanoma in the duodenum.

Melanoma is a malignancy originating from melanocytes. The primary melanoma usually occurs on the skin, retina, anal canal or occasionally at other organs such as the esophagus, penis or vagina. Although melanoma represents about one-third of all metastatic lesions in the gastrointestinal tract, metastasis of melanoma to the GI tract, detected radiologically or endoscopically, is relatively rare. In most cases of malignant melanoma, recurrence and death occur within 10 years after treatment of the primary lesion. We herein report a case showing a recurrence 17 years after extirpation of primary malignant melanoma in the foot. A 65-year-old man, with a history of extirpation of a malignant melanoma in the sole of his foot 17 years before, presented with anorexia and severe anemia, and multiple duodenal tumors were pointed out with upper gastrointestinal endoscopy. Histologic examination of the endoscopic biopsy specimen revealed proliferation of large polygonal cells with distinct nucleoli, and malignant melanoma was diagnosed immunohistochemically. Further examination, including computed tomography and positron emission tomography with fluorodeoxyglucose, revealed systemic metastasis.