Ovarian tumors are most commonly misdiagnosed as uterine leiomyomas. A large pedunculated or exophytic subserosal myoma can sometimes be mistaken for an ovarian tumor. A stalk connecting the myoma with the uterus, two separate ovaries visualized and vascular signal voids between the uterus and mass can help differentiate a subserosal myoma from a primary adnexal tumor. Sometimes, it is difficult to visualize the stalk due to distortion by the huge size of the lesion.

Although CA-125 levels are helpful in differentiating between benign versus malignant ovarian neoplasm, a mildly elevated serum CA-125 is common in patients with uterine diseases as well.

Sertoliform variant of endometrioid carcinoma of ovary is a rare variant that resembles Sertoli and Sertoli-Leydig cell tumors on histology. These tumors arising from the uterus have also been reported.