ENDOMETRIAL SQUAMOUS METAPLASIA - AN UNUSUAL RESPONSE TO PROGESTIN THERAPY OF HYPERPLASIA

Objective.-To report the finding of squamous metaplasia within endomet rial glands occurring as a result of progestin therapy of hyperplasia. Design.-Case series. Retrospective analysis of two cases from 9235 ac cessioned endometrial biopsies. Setting.-Hospital-based pathology labo ratory processing inpatient and outpatient specimens. Patients.-Two wo men, ages 49 and 34 years, with endometrial hyperplasia without squamo us metaplasia who were treated with progestin. Results.-Extensive squa mous metaplasia was found in endometrial glands following progestin th erapy. The posttherapy biopsies also showed progestin-related alterati ons but no evidence of active hyperplasia. Conclusion.-Squamous metapl asia in these eases appears to be a consequence of progestin therapy. The absence of hyperplasia in the progestin-treated endometrium sugges ts that the squamous metaplasia does not represent persistence or prog ression of the original hyperplastic lesion.