Squamous atypia in the atrophic cervical vaginal smear

BACKGROUND Squamous atypia in postmenopausal (PM) cervical vaginal smears (CVS) only rarely is associated with a biopsy-proven squamous intraepithelial lesion (SIL), and thus most commonly represents an atrophy-associated benign reactive change. METHODS To distinguish atypical squamous cells of undetermined significance (ASCUS) and SIL from atrophy-associated benign reactive changes, a review of atypical atrophic PM CVS was performed. Ninety CVS exhibiting an atrophic smear pattern were considered appropriate for study. Repeat smears and/or biopsy after local estrogen therapy were requested to distinguish atrophic/reactive from dysplastic changes. RESULTS Generally, atrophic CVS exhibit uniform nuclear enlargement in the squamous cell population, which, using the criterion of nuclear enlargement alone, would qualify the majority of these cases to be classified as ASCUS. The nuclear enlargement associated with atrophy resolves with the local application of estrogen. Follow-up after local estrogen treatment was available for 84 of 90 patients and revealed 10 cases of SIL (12%) and 9 cases of ASCUS (11%), 6 of which were favored to be of a reactive etiology. Nuclear features most commonly noted in the cases considered to be ASCUS (nonreactive) and SIL were nuclear hyperchromasia and nuclear contour irregularities. CONCLUSIONS Nuclear enlargement alone is not sufficient for diagnosing ASCUS or SIL in PM CVS. Nuclear enlargement in squamous cells is an expected normal reactive change present in PM CVS that resolves with the application of local estrogen. Nuclear hyperchromasia and irregular nuclear contours remain the most reliable cellular characteristics for diagnosing SIL in atrophic CVS. [See editorial on pages 200-1, this issue.] Cancer (Cancer Cytopathol) 1998;84:218-225. © 1998 American Cancer Society.