A 31-year-old woman presents with palpitations, weight loss, tremor and a neck that is clinically normal for thyroid enlargement. Ultrasound shows an 8 cm right ovarian mass. She has biochemical thyrotoxicosis with a suppressed TSH. Which ovarian tumour best explains this presentation?
- A Sertoli-Leydig cell tumour
- B Serous cystadenoma
- C Struma ovarii ✓
- D Yolk sac tumour
Correct answer: C. Struma ovarii
Explanation
Struma ovarii is a monodermal mature teratoma composed predominantly of thyroid tissue and can secrete sufficient thyroid hormone to cause thyrotoxicosis with a normal-sized neck gland. Sertoli-Leydig tumours cause virilisation through androgens, not thyroid hormone, and serous cystadenomas are non-functional. Yolk sac tumour secretes AFP and presents as a rapidly growing malignant mass in younger women.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.