Struma Ovarii in Pregnancy: An Uncommon Cause of Hyperthyroidism.

A 28-year-old woman presented with weight loss and tiredness. Investigations revealed hyperthyroidism. She was commenced on treatment and later became pregnant. Her thyroid levels remained raised, and she later underwent an elective cesarean delivery and ovarian cystectomy. Only a partial cystectomy was achieved, and histopathology examination revealed struma ovarii. An isotope uptake scan ((123)I) including her pelvis revealed low uptake in the thyroid gland and an area of high uptake in her pelvis. The cyst was subsequently removed, and within days, her thyroid hormone levels dropped. This case illustrates the importance of considering uncommon causes of hyperthyroidism.