Acute cholecystopancreatitis: Diagnostic accuracy, true frequency, and clinical implications. Insights from the RELAPSTONE multicentre cohort.

BACKGROUND: Cholecystopancreatitis (CCP)-the concurrent presentation of acute biliary pancreatitis (AP) and acute calculous cholecystitis (ACC)-remains poorly characterised and is often diagnosed without adherence to validated criteria. Its true prevalence and clinical implications remain uncertain. AIM: To determine the true frequency of CCP and to characterise its diagnostic, clinical, and temporal profile. METHODS: Post-hoc analysis of the international multicentre RELAPSTONE cohort, applying strict diagnostic validation. Variables were compared across AP, ACC and CCP groups using bivariate and multivariable analyses. RESULTS: Among 3,016 patients, 135 were initially labelled as CCP; leaving 117 (3,9%) confirmed cases after validation. Confirmed CCP represented 11.1% of AP and 12.3% of ACC cases. Most cases (65%) presented simultaneously. Although patients with CCP showed slightly higher rates of organ failure, there were no differences in ICU admission rates or length of hospital stay between patients with CCP and those with isolated AP or ACC. CONCLUSION: CCP is relatively frequent in current practice, but a proportion of cases are misclassified. In most cases, both conditions present simultaneously, and CCP was not consistently associated with worse clinical outcomes or greater disease severity than isolated AP or ACC. Accurate classification is essential to avoid unnecessary antibiotic use and optimize timing of cholecystectomy.