Introduction:
Struma ovarii is an ovarian tumor with thyroid tissue as its predominant component. It usually occurs in older women and presents with abdominal mass, pain and abnormal bleeding. Most patients are euthyroid, but some reports have noted thyrotoxicosis originating from the malignant struma ovarii.
Presentation of case:
A 10 year-old girl presented with tachycardia, normal thyroid exam and thyrotoxicosis. Thyroid scan showed no uptake with increased uptake in right ovary indicative of struma ovarii. The patient underwent oophorectomy and thyroidectomy, Pathology showed papillary thyroid carcinoma limited to the struma ovarii. Following TSH suppressive therapy and treatment with I131, she is totally symptom free.
Discussion:
Struma ovarii should be a possible diagnosis in any female patient with thyrotoxicosis manifestations with normal thyroid scan and examination.