Objective: To report the finding of squamous metaplasia within endometrial glands occurring as a result of progestin therapy of hyperplasia.
Design: Case series. Retrospective analysis of two cases from 9235 accessioned endometrial biopsies.
Setting: Hospital-based pathology laboratory processing inpatient and outpatient specimens.
Patients: Two women, ages 49 and 34 years, with endometrial hyperplasia without squamous metaplasia who were treated with progestin.
Results: Extensive squamous metaplasia was found in endometrial glands following progestin therapy. The post-therapy biopsies also showed progestin-related alterations but no evidence of active hyperplasia.
Conclusion: Squamous metaplasia in these cases appears to be a consequence of progestin therapy. The absence of hyperplasia in the progestin-treated endometrium suggests that the squamous metaplasia does not represent persistence or progression of the original hyperplastic lesion.