Introduction Struma ovarii (SO) is rare, accounting for 0.3–1% of ovarian tumours. So is defined histologically as replacement of at least 50% of the ovarian tissue by thyroid tissue. Malignant transformation occurs in less than 5% of cases, most often into a papillary thyroid carcinoma (PTC). An association with a synchronous cancer of the thyroid gland proper exists.
Methods We present a case of malignant struma ovarii - considering presentation, diagnosis, management and follow-up.
Results A 75 year-old presented with the incidental finding of an ovarian mass on imaging. Pre-operative CA125 was 38 and CT described a 9 cm dermoid cyst. The patient underwent TAH, BSO and omentectomy. Final histopathology reported struma ovarii with co-existing papillary thyroid carcinoma. Post-operative CT confirmed FIGO stage 1A disease. Adjuvant thyroidectomy and radio-active iodine ablation (RAI) therapy were recommended by the multi-disciplinary team (MDT). The patient remained under follow-up, incorporating long-term thyroid-stimulating hormone (TSH) suppression and surveillance of serum thyroglobulin – with no recurrence to date.
Conclusions Patients with malignant SO usually present with non-specific symptoms and early stage disease. Very few cases are identified pre-operatively due lack of characteristic features on imaging, with the most common mis-diagnosis being that of a dermoid cyst. CA 125 has no role. Fertility-sparing surgery, pelvic clearance, thyroidectomy and radio-active iodine ablation therapy have all been described in the management of malignant struma ovarii.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.