Postmenopausal vaginal bleeding is a red flag for endometrial carcinoma. Such carcinomas often arise in the setting of endometrial hyperplasia. Increased estrogenic stimulation is thought to drive this process, and risk factors include obesity, type 2 diabetes mellitus, hypertension, and infertility. Choriocarcinomas are gestational in origin. A submucosal leiomyosarcoma could produce vaginal bleeding, but the uterus would be enlarged because leiomyosarcomas tend to be large masses. Malignant mullerian mixed tumors are much less common than endometrial carcinomas, but they could produce similar findings. Malignant mullerian mixed tumors are typically uterine neoplasms that have glandular and stromal elements; the malignant stromal component can be heterologous and may resemble mesenchymal cells that are not ordinarily found in the myometrium, such as cartilage. Squamous carcinomas of the endometrium are rare, and more likely to arise in the cervix.