Clinicopathological Evaluation of Gallbladder Lesions in Cholecystectomy Specimens with Special Emphasis on Incidentally Detected Cases of Gallbladder Carcinoma: An Immunohistochemical Study of Cytokeratin 7 and Cytokeratin 20

Abstract

Background and objective: Cholecystectomy specimens exhibit a wide clinicopathological spectrum, ranging from common non-neoplastic diseases to rare neoplastic lesions. Histopathological examination remains the gold standard for definitive diagnosis. Gallbladder cancers (GBCs) are rare, accounting for 0.5% to 1.09% of all gallbladder lesions. These cancers are either clinically suspected or incidentally diagnosed following cholecystectomy.

Materials and Methods: This hospital-based cross-sectional study included all cases diagnosed clinically and radiologically as cholecystitis and subsequently subjected to cholecystectomy. Histopathological diagnosis of gallbladder lesions, age and sex distribution across different gallbladder pathologies, association with gallstones, pathological pT staging of malignant cases, and CK7 and CK20 immunohistochemical findings in malignant cases were observed in this study.

Results: A total of 340 gallbladder specimens were examined histopathologically, revealing 12 cases of gallbladder carcinoma. The most common histopathological diagnosis was chronic cholecystitis (79.4%), followed by chronic cholecystitis with cholesterolosis (7.6%) and adenocarcinoma (3.5%). The most common age group for gallbladder lesions was the fourth decade (26.2%). The age range was 9-85 years, with a mean age of 39.4 years. Overall, females (83%) were more commonly affected than males (17%), with a male:female ratio of 1:4.96. Gallstones were present in 89.1% of all cases, including 83.3% of malignant cases. Incidentally detected gallbladder carcinoma represented 1.17% of the cases, with adenocarcinoma NOS being the most common histopathological type. Pathological pT staging was limited to pT1 and pT2, indicating early-stage disease. CK7 positivity was observed in 91.6% of cases, while CK20 positivity was found in 16.7% of cases. Both CK7 and CK20 were positive in 16.7% of cases, while both were negative in one case (8.33%).

Conclusion: While chronic cholecystitis remains the most common histopathological diagnosis in gallbladder specimens, the possibility of incidental malignancy should be ruled out by mandatory routine histopathological examination of all cholecystectomy specimens.