An Intestinal Melanoma of Unknown Origin Presenting as an Intussusception: A Case Report of a Rare Entity

Melanoma involving the gastrointestinal (GI) tract is an exceedingly rare and clinically challenging entity, often presenting with nonspecific symptoms that can delay diagnosis and treatment. This report describes the case of a 74-year-old male with a history of melanoma of unknown primary origin who presented with acute intestinal obstruction secondary to metastatic melanoma in the small intestine. The patient's clinical course was complicated by intermittent subocclusion, anemia, and hemodynamic instability, culminating in exploratory laparotomy and resection of the affected intestinal segment. Histopathological examination confirmed metastatic melanoma, positive for SOX10, HMB45, and Ki67 markers. This case highlights the diagnostic and therapeutic challenges of GI melanoma, emphasizing the importance of considering rare malignancies in patients with atypical abdominal symptoms, particularly those with a history of melanoma. The discussion underscores the aggressive nature of GI melanoma, the role of surgery as the primary treatment modality, and the need for further research into systemic therapies to improve outcomes in this patient population.