A Case of Primary Small Bowel Melanoma Diagnosed by Single-Balloon Enteroscopy.

Although metastasis from cutaneous malignant melanoma to the small intestine is not uncommon, primary small bowel melanoma (SBM) is extremely rare. This case report describes a rare case of primary SBM, diagnosed by single-balloon enteroscopy. A 74-year-old man presented with recurrent melena. Upper endoscopy and colonoscopy were unremarkable. Abdominal computed tomography (CT) revealed an ileal mass with ileo-ileal intussusception. Subsequent single-balloon enteroscopy identified an ileal tumor, which was histologically diagnosed as melanoma. Extensive clinical examination did not reveal any primary cutaneous lesions. To the best of our knowledge, this is the first case of primary SBM in South Korea.