Struma ovarii (SO) is a rare ovarian teratoma mostly made of thyroid tissue, with papillary thyroid carcinoma (PTC) being even rarer. This report presents a 50-year-old woman with PTC in SO and a normal thyroid. A left ovarian cyst was detected by ultrasound and confirmed by MRI. Surgery included total abdominal hysterectomy with bilateral salpingo-oophorectomy, revealing focal PTC and no thyroid abnormalities. A review of 10 cases showed a median diagnosis age of 46.5 years, with symptoms like abdominal pain and vaginal bleeding. Routine checkups in perimenopausal women are key for early detection, and thyroid evaluation is important in PTC cases within SO.