Primary malignant melanoma of the small intestine: report of a case.

The small intestine is the most common site of gastrointestinal (GI) metastases from cutaneous malignant melanoma; however, primary malignant melanoma originating in the small intestine is extremely rare. We report the case of a 72-year-old man found to have a primary malignant melanoma in the ileum. The patient presented with anorexia, weight loss, diffuse colicky abdominal pain, and episodic rectal bleeding. A preoperative diagnosis of a small intestinal tumor was based on the findings of enteroclysis and computed tomography scanning. This diagnosis was confirmed at laparotomy and an enterectomy was performed. Histopathological examination of the resected specimen clarified the exact nature of the lesion, confirming the diagnosis of melanoma. A thorough postoperative investigation did not reveal a primary lesion in the skin, anus, oculus, or any other location. Thus, we diagnosed this tumor as a primary lesion. One year after his operation, the patient remains well without any evidence of recurrence. Primary malignant melanoma of the small intestine is an extremely rare lesion, which must be differentiated from other intestinal tumors.