SEROTONIN-MEDIATED COLONIC HYPERMOTILITY AS A POSSIBLE CAUSE OF SIGMOID VOLVULUS IN CARCINOID SYNDROME: A CASE REPORT AND PATHOPHYSIOLOGICAL HYPOTHESIS

Abstract

Neuroendocrine tumors are uncommon malignancies that arise from hormone-producing cells of the diffuse neuroendocrine system. Some of these tumors secrete vasoactive substances such as serotonin, producing the constellation of symptoms known as carcinoid syndrome. The syndrome is classically characterized by episodic flushing, secretory diarrhoea, bronchospasm, and cardiac valvular abnormalities. Although gastrointestinal manifestations are frequent in carcinoid syndrome, acute mechanical obstruction of the bowel is rarely encountered. Neuroendocrine tumors and its management are riveting in teams of research, considering its etiopathology and prognosis. Among those pancreatic neuroendocrine tumors are of significance in terms of oncology and surgical gastroenterology. Tumours such as insulinoma, gastrinoma, non-functional tumours are more frequently encouraged, but carcinoid tumour of head of pancreas is having less incidence and a higher malignant potential. This is a case report of a 73-year-old male with a previously diagnosed carcinoid tumor of the pancreatic head with hepatic metastases, who presented with symptoms of acute intestinal obstruction. Imaging revealed characteristic findings of sigmoid volvulus. Emergency exploratory laparotomy confirmed torsion of the sigmoid colon, which was managed by detorsion and sigmoidopexy. This case explores a possible relationship between carcinoid syndrome and sigmoid volvulus. Although such an association is uncommon, this report highlights the need to consider atypical surgical emergencies in patients with neuroendocrine tumors presenting with acute abdominal symptoms.