Use of double-balloon enteroscopy to diagnose a primary intestinal melanoma

A 59-year-old white man presented to his cardiologist with palpitations and lightheadedness. The patient was found to have microcytic, hypochromic anemia, with a hemoglobin level of 6.8 gm/dL. After transfusion of blood products to establish hemodynamic stability, upper and lower endoscopies were performed, the findings of which were not revealing. A small bowel follow-through was also done, which was nondiagnostic and was followed by a capsule endoscopy. A suspicious nodule, with prominent mucosa and luminal narrowing, was noted in the ileum (Fig. 1), and the patient underwent a colonic approach double-balloon enteroscopy, which showed a 4to 5-cm hard, friable, ulcerated mass 2.35 m from the ileocecal valve (Fig. 2). Multiple biopsy specimens were obtained, and the area was tattooed with India ink. Histologically, malignant melanoma was noted, staining positive for S-100, HMB-45, and MelanA. The immunohistochemical stain with MelanA showing nests of malignant cells in the lamina propria is shown in Figure 3. The patient successfully underwent a laparoscopic segmental ileal resection and recovered uneventfully postoperatively. Postoperative evaluation included a complete ophthalmologic and dermatologic examination, neither of which revealed any aberrancy. Furthermore, CTand positron emission tomography scans of the head, chest, abdomen, and pelvis were performed and did not reveal a primary source of malignancy. Because of the paucity of available literature on the treatment of primary intestinal melanoma and localization of the disease, the patient did not receive chemotherapy treatment. At 6-month follow-up, the patient was asymptomatic and free of disease. Primary intestinal melanoma is rarely noted. The diagnosis is one of exclusion, with a need to rule out metastatic disease. Eighteen cases of primary intestinal melanoma are documented in the literature. Several models for the development of melanoma as a primary tumor in the intestine have been proposed, with the amine precursor uptake decarboxylase cell concept being most researched. The proposed mechanism is that of these multipotential cells migrating through the body via the umbilical-mesenteric canal and localizing in the terminal ileum, which in fact is the most common site of intestinal melanoma. A surgical approach is usually undertaken in the treatment of this disease. The reported median survival is 16 months, although this is based on only 15 cases. Neither chemotherapy nor radiation is usually offered to these patients. Based on our literature review, we report the first case of primary intesti-