Struma Ovarii with Follicular Thyroid Carcinoma

Abstract

Struma ovarii (SO) is a rare ovarian tumor, constituting 1% of all ovarian tumors and 3% of ovarian teratomas, predominantly composed of thyroid tissue. While typically benign, SO can undergo malignant transformation. We report a case of a 41-year-old woman with a six-month history of abdominal distention. Imaging revealed a solid cystic mass in the right adnexa with ascites and elevated CA125 levels. The surgical intervention included a hysterectomy and bilateral salpingo-oophorectomy, with pathology confirming struma ovarii with follicular thyroid carcinoma. Postoperative recovery was uneventful, and all follow-up tests were normal. This case underscores the diagnostic challenge posed by SO due to its resemblance to ovarian cancer and highlights the importance of thorough exploration, pathological examination, and long-term follow-up. Serum thyroglobulin levels can be an effective marker for monitoring tumor recurrence. Our findings contribute to the understanding and management of SO with malignant transformation.