Surgical treatments of recurrent small intestine metastatic melanoma manifesting with gastrointestinal hemorrhage and intussusception: A case report

BACKGROUND Melanoma is the most aggressive form of skin cancer, with a tendency to metastasize to any organ. Malignant melanoma is the most frequent cause of skin cancer-related deaths worldwide. Small intestine cancers especially small intestine metastases are relatively rare. Small intestine metastases are seldom described and likely underdiagnosed. Intussusception is most common in pediatric age, and in adults are almost 5% of all cases. CASE SUMMARY A 75-year-old man with a history of acral malignant melanoma was admitted to the Gastroenterology Department of our hospital, complaining of intermittent melena for 1 mo. Magnetic resonance enterography showed partial thickening of the jejunal wall and formation of a soft tissue mass, indicating a neoplastic lesion with jejunojejunal intussusception. The patient underwent partial small bowel resection. Pathological findings and immunohistochemical staining indicated small intestine metastatic melanoma. The patient refused further anti-tumor treatment after the surgery. Ten months after the first surgery, the patient presented with melena again. Computed tomography enterography showed the anastomotic stoma was normal without thickening of the intestinal wall, and routine conservative treatment was given. Three months later, the patient developed melena again. The patient underwent a second surgery, and multiple metastatic melanoma lesions were found. The patient refused adjuvant anti-tumor treatment and was alive at the latest follow-up. CONCLUSION Small intestine metastatic melanoma should be suspected in any patient with a history of malignant melanoma and gastrointestinal symptoms.