Acute small bowel obstruction due to intussusception of malignant amelonatic melanoma of the small intestine.

Malignant melanoma is a common malignancy and cutaneous melanoma showed an unusual prediction to metastasise into the small intestine. At autopsy metastatic deposits found in 50-60%, but less than 2-4% of melanoma patients diagnosed to have gastrointestinal (GI) metastasis during the disease course and 4-9% GI melanoma had unknown primary melanoma, which should be considered metastatic because primary lesion may be very small to diagnose or had regressed spontaneously. Few cases reported to have intussusception as a presenting feature. We report a case of amelanotic metastatic melanoma presented with intussusception and without known primary melanoma. The patient presented with abdominal pain, vomiting and distension. He was diagnosed as having acute intestinal obstruction as confirmed by erect abdominal x-ray. Ultrasonography showed small intestine intussusception. Emergency laparotomy revealed ilieo-ileal-type intussusception with intraluminal mass, which was resected and end-to-end anastomosis of bowel was performed. Histopathological and immunohistochemical examination of the resected specimen showed amelanotic melanoma.