Squamous Cell and Adenosquamous Carcinoma of Gall Bladder: a Clinicopathological Study of 8 Cases Isolated in 94 Cancers

Adenosquamous/squamous cell carcinoma (AS/SCC) of the gall bladder is a rare histopathologic subtype that accounts for 1 to 12% of all the gall bladder carcinomas (GBC). Literature on these malignancies is limited. A retrospective analysis of 8 cases (study group) of pathologically proven AS/SCC of the gallbladder among 94 patients who underwent surgery for GBC from January 2001 to December 2014 was done. Twenty-four conventional gall bladder adenocarcinoma cases were selected as control group after matching for age and gender. Mean patient age was 57.8 years and six were females. Clinical presentation did not seem to be too different among the study and control group. Average tumor thickness was significantly higher in AS/SCC cases as compared to the control group (mean 3.1 versus 1.44 cm; p = 0.001). Immunohistochemistry for Ki-67 in adenosquamous carcinoma of the gall bladder showed much higher proliferative index in squamoid area than the adenocarcinoma areas (mean 31.3 versus 16.8%; p = 0.0004). Study group showed 87.5% patients were in higher stage whereas only 37.5% of the patients in control group presented at a higher stage. AS/SCC of the gall bladder presented at an advanced stage. Higher proliferation index in squamous component of adenosquamous carcinomas may account for higher T stage in these malignancies.