Navigating through perplex morphologic changes after exogenous hormone usage.

Clinical application of exogenous hormone as a method of contraception and/or treatment of various gynecologic disorders is exceedingly common. Unfortunately, the concurrent use of these agents also complicates the interpretation of pathology specimens. Various studies have shown that morphologic changes induced by hormonal therapies are present in both non-neoplastic and neoplastic tissues within the women's reproductive tract. It is important to understand the exogenous hormone induced morphologic changes, as it helps the pathologists make the accurate diagnosis, and in turn, guide clinicians to make optimal clinical decisions. In this review, we summarize the morphologic changes in both neoplastic and non-neoplastic endometrial, cervical, and myometrial surgical specimens after hormonal therapies, particularly after progestin treatment. In the endometrium, particularly in the scenario of progestin-treated atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN), there is notoriously poor interobserver agreement and difficulty in assessing for the residual disease. We summarize current literature and propose our recommended approach in assessing these challenging endometrial biopsies, including a diagnostic algorism, the use of PAX-2, PTEN, beta-catenin immunohistochemistry panel, as well as consistency in diagnostic wording of the report. In the cervix, progestin makes dysplastic lesions appear metaplastic, thus high-grade squamous dysplastic lesions may be easily missed. Within the myometrium, lesions such as adenomyosis may show various degree of decidualization, while smooth muscle neoplasms may show apoplectic changes, and stromal lesions including endometrial stromal sarcoma may show more eosinophilic cytoplasm. All such changes may pose more or less diagnostic challenges in our daily practice. However, most are readily recognizable when we understand particular hormone related scenarios.