A Challenging Case of Malignant Struma Ovarii With Concurrent Papillary Thyroid Cancer

Struma ovarii is a rare type of ovarian tumor that is predominantly composed of thyroid tissue. The majority of these are benign, with malignant struma ovarii (MSO) comprising only 5-10% of all cases. A 41-year-old female with a history of ovarian cystectomy for bilateral dermoid cysts presented with gallstone pancreatitis. Computed tomography (CT) scan revealed adnexal masses, peritoneal nodules, and a thyroid nodule. Surgery, including total hysterectomy and salpingo-oophorectomy, showed MSO and differentiated follicular carcinoma. Subsequent thyroidectomy revealed multifocal papillary thyroid carcinoma. Postoperative radioactive iodine therapy was given, and the patient has recovered fully. MSO may present as an ovarian mass, and the mainstay treatment is surgical resection. The rarity of this condition requires a multidisciplinary approach for optimal management. MSO should be considered in the differential diagnosis of ovarian masses. Early and accurate diagnosis, followed by appropriate surgical and adjuvant therapies, can lead to favorable outcomes.