Glassy cell carcinoma of the uterine cervix: histochemical, immunohistochemical, and molecular genetic observations.

Glassy cell carcinoma (GCC) of the uterine cervix is characterized by distinctive cytological features and an aggressive clinical course. Although this tumor has been usually considered a poorly differentiated variety of adenosquamous carcinoma (ASC), a clarification of the phenotype and histogenesis of GCC is still required. We examined three GCCs and four ASCs for histochemical and immunohistochemical phenotypes and molecular genetic status, comparing them with five nonkeratinizing squamous cell carcinomas and five endocervical-type mucinous adenocarcinomas. GCCs had a profile of cytokeratin expression similar to that of reserve cells or immature squamous cells of the cervix. In addition to squamous differentiation, GCCs sporadically produced intestinal-type mucin. HPV 18 was detected in two of three GCCs and two of four ASCs. GCCs may originate from multipotential stem or reserve cells that undergo early squamous differentiation. The presence of HPV 18 might stimulate biphasic squamous and glandular differentiation.