Heterotopic Pancreas in the Gallbladder: An Incidental Finding Following Laparoscopic Cholecystectomy in a Patient With Cholelithiasis.

Heterotopic pancreas (HP)-defined as ectopic pancreatic tissue lacking vascular or ductal connections to the main organ-represents an exceedingly rare anatomical variant in the gallbladder. This developmental anomaly warrants careful clinical attention due to its potential surgical implications. We report a case of a 38-year-old female who presented to the emergency department with progressive abdominal pain, nausea, and vomiting. Ultrasonographic evaluation revealed a solitary 15-mm gallstone without evidence of gallbladder wall inflammation. Following laparoscopic cholecystectomy, histological examination of the 7.5 cm × 3 cm specimen demonstrated acute-on-chronic cholecystitis with localized cholesterolosis. Microscopic evaluation revealed heterotopic pancreatic tissue beneath the gallbladder fundus serosa. The tissue displayed complete pancreatic architecture-including acini, ducts, and islets of Langerhans-without evidence of malignancy or dysplasia. The patient experienced an uncomplicated postoperative course, with complete symptom resolution during follow-up. This case emphasizes the importance of thorough histopathological examination in identifying rare anatomical variants and contributes to the limited literature on gallbladder HP. While typically asymptomatic, recognition of HP remains crucial for appropriate surgical planning and patient management.