Adenosquamous carcinoma in the biliary tract: association of the proliferative ability of the squamous component with its proportion and tumor progression

AbstractObjectives: The purpose of this study was to evaluate the association of the proliferative ability of squamous cell carcinoma (SCC) component with its proportion and tumor progression in adenosquamous carcinoma (ASC) in the biliary tract.Methods: Nine patients with ASC in the biliary tract (four each in the gallbladder and the extrahepatic bile duct and one in the ampulla of Vater) who underwent surgical resection were retrospectively reviewed.Results: The proportion of the SCC component in the primary sites ranged from 30% to 95%. The Ki-67 index of the SCC component was higher than that of the adenocarcinoma component in all cases, regardless of the component ratio in the patients’ primary lesions. Predominance of the SCC component in the advancing region of the tumor, in angiolymphatic invasion and in perineural invasion was observed in most of the cases. The component ratio in metastatic lymph nodes differed from that in the corresponding primary lesions in all six cases with lymph node metast...