How accurate is transvaginal ultrasound in distinguishing between malignant cysts and benign cysts in pcos? can they be misinterpreted?

Misinterpreted, but: TVUS is helpful, but limited in distinguishing benign vs. malignant ovarian cysts. There are US features, coupled with clinical data and blood testing in select cases, that go a long way toward assessing risk. There are research protocols (e.g. MD Anderson) for ovarian cancer screening. The cyst(s) in PCOS would rarely be confused for malignancies, the look and clinical history are different.

Extremely good: U/S is very good at seeing the b-9 or malignant features of ovarian cysts. The cysts of PCOS are small, like a string of pearls around the edge of the ovary. They are not malignant. A malignant cyst looks totally different--It is larger and has fluid and solid components. U/S isn't perfect but is the best tool in the box for evaluating ovarian cysts without surgically removing the ovary.