Primary Intestinal Melanoma: An Exceptional Case Report

Abstract

Primary melanoma of the small bowel is an exceptionally rare and aggressive entity, often difficult to distinguish from metastatic disease and frequently diagnosed at an advanced stage. A 17-year-old patient presented with acute diffuse abdominal pain, fever, and vomiting. On admission, he was hemodynamically unstable with signs of generalized peritonitis. Laboratory tests showed leukocytosis, elevated inflammatory markers, and severe anemia. Abdominal CT revealed pneumoperitoneum, abundant peritoneal fluid, and a small bowel mass. Emergency surgery identified a perforated 10 cm small bowel tumor located 60 cm distal to the first jejunal loop, with generalized peritonitis. Segmental resection with primary anastomosis was performed. Histopathological and immunohistochemical analysis confirmed malignant melanoma. Despite immunotherapy, the patient developed diffuse peritoneal carcinomatosis and died six months later. Primary small bowel melanoma is a rare condition that may present with acute complications such as perforation. Prognosis remains poor despite surgical and systemic treatment.