IntroductionEctopic pancreas tissue (EPT) or pancreatic heterotopia is a rarely observed congenital abnormality defined as the presence of pancreatic tissue in another organ without any anatomical or vascular connection to the pancreas. The term consists of the two Greek words ”hetero-” which means ”other” and ”-topia” which means ”site”, pointing out the unique location of pancreatic cells. EPT’s favored sites are the stomach, duodenum, colon, jejunum, and Meckel’s diverticula (1). The gallbladder is a highly infrequent location for EPT (2). Almost all cases are detected incidentally during the histopathological examination after cholecystectomy for other pathologies. The prevalence of EPT in the gastrointestinal tract varies from 0.6% to 13.7% in autopsy series and 0.2% in laparotomies (3, 4). Although the malignant transformation of this tissue is not frequently expected, pathologists must be aware of it to ensure no malignant pathology is present and prevent further misdiagnosis. In this study, we present a case of EPT that we found incidentally during the histopathological examination of the specimen from the gallbladder in a patient who underwent cholecystectomy due to acute cholecystitis.Case HistoryA 40-year-old male was referred to the emergency department for acute pain in the right upper quadrant of the abdomen. The pain was constant and initiated hours before and intensified when he had dinner. He also reported fever, anorexia, nausea, and one involuntary vomiting episode containing only stomach contents. Besides intellectual disability and epilepsy, patient’s medical history was unremarkable otherwise. He was on Valproate(200mg/D), Risperidone(1mg/BD) and Clonazepam(1mg/HS). He denied smoking and any recreational drug use. No allergies were reported. During the clinical examination, his vitals were slightly above normal ranges (Blood pressure: 115/70mmHg; Heart rate: 108bpm; Respiratory rate: 19 breaths/min; Temperature: 37.9°C; Oxygen saturation: 99% without supplemental oxygen). The palpation of the abdomen revealed tenderness in the right upper quadrant and a positive Murphy sign with no rebound tenderness or guarding. The laboratory evaluation was within normal range except for a WBC count of 10300, ESR of 32, and a 2+ CRP. Additionally, he underwent an ultrasonographic evaluation of the upper abdomen, reporting a thickened wall gallbladder containing multiple stones (measuring up to 8x10mm). The patient was scheduled for emergency laparoscopic cholecystectomy under the diagnosis of acute calculous cholecystitis. During surgery, the gallbladder was found to be gangrenous. The patient had a complicated postoperative period due to surgical wound infections and was hospitalized for a week to receive intravenous antibiotics; however, he did not report any delayed complications or symptoms after discharge.