Large Necrotic Mass in the Small Bowel.

Melanoma of unknown primary (MUP) is a melanoma found in sites other than the skin, mucosa, or eye. It is most commonly present in lymph nodes and least frequently in visceral organs. Diagnosis is difficult given its internal presentation and is often late stage with poor prognosis. We report an 89-year-old man who presented with weakness, a 27-kg weight loss, and gastrointestinal bleeding. He was found to have a large necrotic mass in the small bowel consistent with melanoma. Although he had extensive skin, anogenital, and ocular examinations, no cutaneous lesion was identified, therefore leading to a diagnosis of MUP.