Distribution of cell types differs in Papanicolaou tests of squamous cell carcinomas and adenocarcinomas

Abstract

Successful cervical cancer screening has led to decreasing numbers of malignant Papanicolaou tests in most laboratories. A previous study demonstrated a greater trend to unsatisfactory Papanicolaoutests in women with squamous carcinoma when compared with adenocarcinoma cases. However, adenocarcinomas were less frequently recognized as malignant. In an effort to elucidate differences in Papanicolaou tests from these tumor types, the relative distribution of cells was blindly and semi-quantitatively assessed in ThinPrep Papanicolaou slides from 332 women with biopsy-proven squamous carcinoma (237 cases), adenocarcinoma (45), and noninvasive lesions (50). Significant differences (P <0.0001) among the three categories were observed in total cellularity, amount of blood and diathesis, normal endocervical cells, and normal squamous cells. When slides from squamous carcinomas and adenocarcinomas were compared, the amount of blood (P < 0.4) and presence of diathesis (P > 0.004) were more prominent in squamous carcinomas. The number of endocervical cells (P<0.0001) was greater in adenocarcinomas, but adenocarcinomas were less likely to be recognized as malignant. This systematic evaluation reinforces earlier suggestions that the presence of blood and tumor diathesis allow easier recognition of squamous carcinoma. A more detailed analysis of adenocarcinoma's cellular characteristics in Papanicolaou tests is needed to understand the reasons for undercalls in this tumor type.