Incidental diagnosis of gallbladder carcinoma during or after routine cholecystectomy: A retrospective study with emphasis on clinicopathologic findings.

Background: Cholecystectomy is a common surgical procedure routinely performed for patients with benign gallbladder disease. The most common indications for cholecystectomy are acute or chronic cholecystitis with or without cholelithiasis. However, in rare instances, incidental findings ranging from benign to malignant conditions are encountered, of which gallbladder adenocarcinoma is an aggressive and fatal disease.

Aim: To determine the prevalence of all incidental diagnoses in routinely performed cholecystectomy specimens, with a particular emphasis on adenocarcinoma, and to characterize the clinicopathological characteristics of malignant postoperative specimens.

Methods: The electronic medical record and institutional pathology database were searched for analyses done on gallbladder specimens from patients who had a routine cholecystectomy for benign gallbladder disease during the study period (February 2000 to February 2023). A total of 30678 cholecystectomies performed across the study period were included for analysis. Patients who had preoperative findings or radiological results concerning malignancy were excluded. The demographic and clinical data including patient age and gender, preoperative diagnosis, radiographic results at time of diagnosis, gross and morphologic features of gallbladder specimens, and pathologic staging parameters according to the American Joint Committee on Cancer were recorded.

Results: Of the 30678 cholecystectomy specimens received by the Department of Pathology from patients with who had cholecystectomy for putative benign gallbladder disease during the study period, 42 (0.14%) were determined to be incidental gallbladder adenocarcinoma and 1 was adenocarcinoma in situ. There were 2 benign incidental diagnoses, including 9 patients (0.02%) with accessory/ectopic liver lobe, and 3 with paraganglioma.

Conclusion: Thorough histopathological examination of routine gallbladder specimens is important to provide an early diagnosis of unexpected gallbladder cancer to ensure that patients receive timely care when the disease is treatable.