Application of cytomorphologic features and immunocytochemistry to cervicovaginal smears. A scoring system to distinguish between endometrial and endocervical adenocarcinoma.

Objective: To apply cytomorphologic features and a limited panel of immunocytochemistry to cervicovaginal smears to distinguish between primary endocervical adenocarcinoma (ECA) and primary endometrial adenocarcinoma (EMC).

Study Design: The study was a retrospective analysis of 35 cases, of which 21 were of primary endometrial origin and 14 were of primary endocervical origin. In all cases included in the study, the site of origin of adenocarcinoma was confirmed by examination of the surgical specimen. Twenty-four cytomorphologic characteristics and a limited panel of antibodies (estrogen receptor, carcinoembryonic antigen and vimentin) were applied to conventional cervicovaginal smears to ascertain whether a combination of these would be sufficiently distinctive to allow reliable distinction between ECA and EMC. The slides were scored using defined cytomorphologic characteristics and immunocytochemistry. The score was calculated by using the receiver operating curve (ROC).

Results: Statistical analysis identified 7 variables that were significant in distinguishing between ECA and EMC: necrosis, altered blood, histiocytes, strips of cells, palisading of cells, pseudorosettes and positive immunocytochemical staining for carcinoembryonic antigen. Using the ROC, a numerical score < 4 was indicative of an EMC and a score > or = 4 of ECA.

Conclusion: This study found that the proposed scoring system based on these 7 variables could reliably distinguish between ECA and EMC and assist in definitive management of patients.