Light micrograph of endometrial carcinoma, endometrioid type, FIGO Grade 1 at low magnification. Endometrial carcinoma is the cancer of the lining of the womb, the endometrium. Endometrial carcinoma is the cancer of the lining of the womb, the endometrium. It consists of crowded irregularly-shaped glands lined by mildly atypical columnar epithelium. The glands are separated by delicate strands of stroma. Uterine cancer is the most commonly diagnosed invasive cancer of the female genital tract. The vast majority of these arise in the endometrium (lining of the womb) and are endometrioid subtype. Endometrial cancer mostly affects postmenopausal women. The most common risk factor is prolonged exposure to estrogen. Patients usually present with abnormal uterine bleeding.