Small bowel obstruction due to metastasis of cutaneous melanoma: 7-years after primary diagnosis.

Aim of study: Metastatic involvement of the small bowel by melanoma is rare. The average time from the excision of the primary cutaneous melanoma to the occurrence of intestinal metastases tends to be between 3 and 5 years; one case of recurrence after 15 years is described. The most common kind of lesion is polypoid: this can cause intussusception and intestinal occlusion. We report a case of intestinal occlusion by an ileal metastasis of a melanoma occurred 7 years earlier. Materials and Methods: Case Report: The patient was a 57-year-old female who was admitted to our hospital for persistent abdominal pain and sub-occlusion. The patient's past medical history included cutaneous malignant melanoma 7 years before and lobular breast adenocarcinoma 10 years before. During the previous three months, she had intermittent abdominal pain and a weight loss of about 7 kg. Abdominal-US, EGDS and colonoscopy were all negative for pathologic findings. During the hospital stay, a CT enterography revealed lower intestinal intussusception, and enlarged lymph nodes both in the abdominal cavity and in the retroperitoneum. Intraoperatively we found an ileal invagination due to a polypoid mass of the ileal tract. Segmental ileal resection was performed; wide mesenteric lymph node dissection was not possible because of large and extended retroperitoneal lymphadenopathies. Histological examination showed epithelioid and spindle tumor cells with obvious cytoplasmic melanin deposition. Immunohistochemical staining revealed that tumor cells were positive for S-100, HMB-45 and vimentin, confirming the diagnosis of melanoma. Main results and conclusions: Appearance of GI metastases is reported up to 15 years after the inital diagnosis of melanoma. Reported clinical signs and symptoms generally include chronic abdominal pain, occult or gross bleeding and, as in this case, weight loss. Aspecificity of symptoms may impede early diagnosis and treatment of the disease. As in this case, where curative surgery is impossible because of the extent of disease, metastatic tumor resection or GI tract bypass surgery is recommended to relieve symptoms or avoid future complications. Early diagnosis of metastases requires adequate imaging (CT) and prolonged follow up.