A rare incidental finding during routine pathological evaluation of gallbladder specimen: a case report

Neuroendocrine tumors (NETs) of the gallbladder are rare, often discovered incidentally, with unclear pathogenesis and management strategies.

A 51-year-old man with hypertension presented with abdominal pain and a positive Murphy's sign. After laparoscopic cholecystectomy for suspected acute cholecystitis, histopathology revealed a grade 1 NET at the cystic duct margin, invading the subserosa (pT2). Staging showed no metastases, though pericholedochal lymph nodes were enlarged. A second surgery resected the cystic duct and regional lymph nodes, revealing no residual tumor. No adjuvant therapy was given, and the patient remains disease-free at 5 years.

Gallbladder NETs often mimic common biliary conditions, making the preoperative diagnosis challenging due to nonspecific findings. This case highlights the pathology's key role in the diagnosis of asymptomatic early-stage tumors and suggests a favorable prognosis for well-differentiated NETs with surgical management, despite unclear adjuvant therapy guidelines.

NETs of the gallbladder are uncommon with nonspecific clinical and imaging features. This rare case emphasizes the importance of routine pathological examination of gallbladder specimens in detecting and grading of asymptomatic and early stage tumors such as NETs.