Endometrial intraepithelial neoplasia (EIN) is a premalignant lesion of the uterine lining that predisposes to endometrioid endometrial adenocarcinoma. It is composed of a collection of abnormal endometrial cells, arising from the glands that line the uterus, which have a tendency over time to progress to the most common form of uterine cancer—endometrial adenocarcinoma, endometrioid type. History
EIN lesions have been discovered by a combination of molecular, histologic, and clinical outcome studies beginning in the 1990s which provide a multifaceted characterization of this disease. They are a subset of a larger mixed group of lesions previously called "endometrial hyperplasia". The EIN diagnostic schema is intended to replace the previous "endometrial hyperplasia" classification as defined by the World Health Organization in 1994, which have been separated into benign (benign endometrial hyperplasia) and premalignant (EIN) classes in accordance with their behavior and clinical management. EIN should not be confused with an unrelated entity, serous intraepithelial carcinoma ("serous EIC"), which is an early stage of a different tumor type known as papillary serous adenocarcinoma that also occurs in the same location within the uterus. Clinical aspects
The average age at time of EIN diagnosis is approximately 52 years, compared to approximately 61 years for carcinoma. The timeframe and likelihood of EIN progression to cancer, however, is not constant amongst all women. Some cases of EIN are first detected as residual premalignant disease in women who already have carcinoma, whereas other EIN lesions disappear entirely and never lead to cancer.
Conjugated estrogens/medroxyprogesterone acetate (CEs/MPA), sold under the brand names Prempro and Premphase, is a combination product of conjugated estrogens (Premarin), an estrogen, and medroxyprogesterone acetate (Provera), a progestogen, which is used in menopausal hormone therapy for the treatment of menopausal symptoms.In 2017, it was the 294th most commonly prescribed medication in the United States, with more than one million prescriptions. See also
Estradiol/medroxyprogesterone acetate
Estradiol cypionate/medroxyprogesterone acetate
List of combined sex-hormonal preparations

References
External links
"Estrogens mixture with medroxyprogesterone acetate". Drug Information Portal. U.S. National Library of Medicine.