Snapshot A 60-year-old G0 female was found on outpatient endometrial biopsy to have abnormal proliferation of stromal and glandular endometrial elements. Overview Introduction An estrogen-dependent hyperplasia affecting mainly postmenopausal women incidence peaks between ages 50 and 60 Risk factors include increased estrogen exposure unopposed postmenopausal estrogen replacement obesity nulliparity late menopause (after age 52) polycystic ovarian syndrome estrogen-producing tumors anovulation cancer syndromes hereditary nonpolyposis colon cancer 3 classes of hyperplasia severity simple ↑ number of glands with no crowding complex ↑ number of branching glands with crowding atypical ↑ number of atypical glands with crowding highest risk of progression to endometrial cancer Presentation Symptoms abnormal uterine bleeding post-menopausal bleeding Evaluation Tissue biopsy gold standard Treatment Pharmacologic progesterone indications simple or complex hyperplasia used to reverse hyperplastic process Surgical hysterectomy indications atypical hyperplasia because of high chance of invasion