Cytomorphological characteristics of glassy cell carcinoma of the uterine cervix: histopathological correlation and human papillomavirus genotyping

A retrospective analysis was performed to describe the cytomorphological and histopathological findings and human papillomavirus (HPV) genotypes for glassy cell carcinoma (GCC) of the uterine cervix. Five cases of cervical GCC, in which the glassy cell features constituted at least 95% of the specimen, were included. Four patients had stage IIB GCCs and one had stage IIIB GCC. All patients underwent concurrent chemoradiation therapy. Based on pretreatment cytology, only 1 of the 5 cases was correctly diagnosed as GCC. The remaining cases were diagnosed as carcinoma of undetermined type, adenocarcinoma, poorly differentiated carcinoma, or unsatisfactory for evaluation. Cytological specimens had moderate cellularity and contained small clusters of tumor cells admixed with amphophilic, granular tumor diathesis. The tumor cells possessed large, round to oval nuclei and abundant, granular, ground-glass cytoplasm. The nuclei exhibited prominent eosinophilic nucleoli. The cytoplasm displayed sharp margins and molding, resulting in "intercellular windows" between neighboring attached cells. HPV genotyping revealed that high-risk HPV types 18, 16, and 31 were detected in 3, 1, and 1 cases, respectively. Consistent with this finding, all cases exhibited block p16 positivity, confirming the association of HPV infection with GCC. In conclusion, a distinct cytoplasmic margin, the characteristic histopathological feature of GCC, was observed in liquid-based cytological preparations. We suggest that sharp cytoplasmic outlines with molding and intercellular windows are characteristic cytomorphological features of GCC. Detection of high-risk HPV in all cases strongly supported the notion that high-risk HPV is involved in the pathogenesis of GCC.