[Jejunal melanoma: An unusual cause of intussusception]

We report the case of a jejunal melanoma revealed by intestinal intussusception in a 75-year-old male. He was admitted for acute abdominal pain associated with vomiting. Clinical examination, combined with abdominal ultrasound and plain abdominal radiography, suggested an obstructive syndrome. Computed tomography revealed an intussusception centered on a jejunal tumor mass. Emergency laparotomy confirmed the presence of an ileo-jejunal intussusception with a palpable jejunal mass. Gross examination of the resected intestinal specimen revealed a solitary sessile polypoid blackish tumor measuring 5cm at its greatest dimension. Microscopic analysis showed a proliferation of large, loosely cohesive cells with pigmented cytoplasm and marked atypia, expressing HMB45 and S100. Histopathological examination confirmed the diagnosis of melanoma. No primary cutaneous, mucosal, ocular, or meningeal lesion was identified during complementary investigations. After 8 months of follow-up, the patient remains in good general condition with no recurrence. This case highlights the complexity of identifying a primary lesion in intestinal melanomas and rekindles the debate on their primary versus secondary origin.