Unveiling the molecular profile of adenosquamous gallbladder carcinoma: characterization of a Caucasian cohort.

Tumours containing more than 25% squamous component are classified as gallbladder adenosquamous carcinomas (gallbladder adenosquamous carcinomas), a rare histological subtype characterized by a significantly worse prognosis than conventional adenocarcinomas.

Nearly all tumours (96%) showed PD-L1 positivity with a combined positive score (combined positive score) greater than 1.

CLDN18.2 expression was identified in 28% of cases, although its confinement to the glandular component may limit its therapeutic applicability.