Incidence and Predictors of Incidental Gallbladder Carcinoma After Cholecystectomy: A Prospective Algerian Multicenter Cohort Study.

INTRODUCTION

Incidental gallbladder carcinoma (IGBC) is an unexpected diagnosis after cholecystectomy for presumed benign disease. Prospective multicenter data from Africa remain limited. We aimed to determine the incidence of IGBC and identify associated factors.

METHODS

This predefined secondary analysis used data from the Algerian Cholecystectomy Outcomes and Determinants Study, a prospective multicenter cohort study conducted across 32 surgical centers in Algeria. Consecutive adult patients undergoing cholecystectomy for presumed benign gallbladder disease between January 1 and June 30, 2025, were included. All gallbladder specimens underwent systematic histopathological examination. The primary outcome was the incidence of IGBC. Associations were explored using univariable logistic regression and age-adjusted Firth penalized likelihood logistic regression to address sparse-data bias.

RESULTS

Among 813 patients, IGBC was identified in eight cases, corresponding to an incidence of 0.98%. Patients with IGBC were significantly older than those without IGBC (mean age 67.4 versus 48.9 y). In the primary age-adjusted model, age was independently associated with IGBC (adjusted odds ratio 1.08 per year, 95% confidence interval 1.01-1.14). Diabetes and conversion to open surgery showed positive but imprecise associations in exploratory analyses.

CONCLUSIONS

In this prospective multicenter North African cohort, 0.98% of cholecystectomies for presumed benign disease revealed IGBC, supporting routine histopathological examination of all cholecystectomy specimens.