AB131. SOH23ABS_106. Adult small bowel intussusception secondary to metastatic malignant melanoma

Background: Malignant melanoma of the gastrointestinal tract (GIT) is a rare presentation. Malignant tumours are a known cause of adult intussusception. Very few cases of small bowel intussusceptions due to metastatic melanoma have been reported. Metastatic melanoma to the GIT is rarely detected preoperatively with the diagnosis being made intraoperatively. Surgery is considered the standard of care for adult intussusception but the literature lacks consensus on the optimal surgical approach.

Methods: A 57-year-old man with a past history of cutaneous malignant melanoma presented with symptoms of bowel obstruction. Examination of the abdomen showed distension, tenderness in the left iliac fossa, and increased bowel sounds. Computerized tomography showed evidence of small bowel obstruction; an exploratory laparotomy was performed which revealed small bowel obstruction secondary to intussusception at the distal ileum with a malignant lead point.

Results: Some studies recommend resection without reduction of the intussusception to prevent the spread of malignancy while others recommend reduction followed by resection. The intussusception was reduced, and 115 cm of small bowel was resected along with mesenteric lymph nodes. Immunochemistry of the specimen was positive for both Melan-A and S-100 confirming malignant melanoma.

Conclusions: The rarity and variability in presentation of adult intussusception makes its diagnosis difficult. The lack of consensus on the best surgical approach also poses some challenges. There should be a high level of suspicion for metastatic gastrointestinal malignant melanoma in a patient who present with acute abdominal pain on a history of malignant melanoma.

Keywords: Adult intussusception; gastrointestinal malignant melanoma; laparotomy; metastatic malignant melanoma; small bowel obstruction