Bilateral malignant struma ovarii with concurrent thyroid carcinoma

Malignant struma ovarii (MSO) is a rare ovarian tumour. The co-occurrence of MSO and thyroid carcinoma is even rarer. There is no established treatment for these patients. We report a postmenopausal woman in her 60s who presented with left hip pain, increased urinary frequency and fatigue. Imaging showed a left adnexal cystic lesion 8.8 cm in diameter and an incidental 12×8 mm right ovarian cyst. She underwent total laparoscopic hysterectomy and bilateral salpingo-oophorectomy, and findings were significant for bilateral stage IA MSO. The metastatic workup showed concurrent papillary thyroid carcinoma. She underwent total thyroidectomy with neck dissection and radioactive iodine (RAI) adjuvant therapy. While thyroid carcinoma management is more standardised, a literature review yielded a wide range of MSO treatments. Recent literature favours conservative management with unilateral salpingo-oophorectomy. RAI therapy in these cases is controversial. We will discuss the literature findings on the optimal treatment of MSO with concurrent thyroid cancer.