Evaluating the Incidence of Incidental Gallbladder Carcinoma in a Tertiary Care Centre: A Retrospective Analysis in North India.

Background Incidental gallbladder carcinoma (IGBC) remains a significant clinical challenge, with its diagnosis often delayed due to the asymptomatic nature of the disease and its incidental discovery post-cholecystectomy. This study's aim is to calculate incidence in a high-risk, region-specific (North Indian) population and also to provide novel insights into clinical presentation as well as macroscopic and histopathological features of IGBC. Material and methods This retrospective observational study spanned four years (August 2013 to July 2016) and included a total of 3096 cases. Demographic, clinical, radiological, treatment and follow-up data were sourced from archived records. IGBC diagnoses were confirmed on formalin-fixed, paraffin-embedded tissue sections stained with hematoxylin and eosin (H&E). Results  A total of 3,067 routine cholecystectomies were performed during this period, of which a total of 162 cases (18.93%) were diagnosed as gallbladder carcinoma (GBC) and 51 cases (1.74%) were identified as IGBC. The mean age was 49.8 years. Among the total IGBC cases, most patients underwent preoperative imaging of which eight cases (15.6%) showed findings on preoperative radiological evaluation suggestive of malignancy. Among these, five cases (9.8%) demonstrated subtle gallbladder wall thickening and three cases (5.8%) revealed suspicious small polypoidal lesions (less than 1 cm). Microscopy showed that majority of these tumours were well-differentiated adenocarcinomas (n=27; 52.94%), followed by moderately differentiated adenocarcinomas (n=17; 33.33%), mucinous adenocarcinomas (n=03; 5.88%), papillary adenocarcinomas (n=02; 3.92%), and neuroendocrine tumours (n=1; 1.96%). Staging revealed 26 (50.98%) cases as Stage IIA, 24 (47.0%) as Stage I, and one (1.9%) as Stage III. On follow-up, the median survival period was found to be 32 months. Conclusions Our study emphasizes the limitations of conventional imaging in detecting early-stage gallbladder cancer, and it advocated the critical importance of routine histopathological examination (HPE) of all gallbladder specimens. Additionally, our findings contribute to a growing body of evidence that suggests early-stage IGBC may offer improved survival outcomes if diagnosed timely and treated aggressively, prompting a re-evaluation of current diagnostic and management strategies.