Coexistence of malignant struma ovarii and Graves' disease

To report an unusual case of hyperthyroidism from Graves' disease that was coexistent with malignant struma ovarii.

We summarize the clinical history, physical findings, laboratory data, imaging studies, pathologic features, and treatment in a patient with recurrent hyperthyroidism and discuss the incidence of ovarian tumors of various histologic origins, including thyroid tissue (that is, struma ovarii).

Five years after diagnosis of Graves' disease and resolution of symptoms with 1 year of antithyroid drug therapy, a 53-year-old woman had recurrence of palpitations, tremors, and weight loss. Results of thyroid function tests showed high total and free thyroxine levels and a low thyrotropin level. Thyroid radioiodine uptake was high (69% at 24 hours). Abdominal ultrasound studies disclosed a cystic mass in the right adnexal area. Total abdominal hysterectomy and bilateral oophorectomy revealed a 7.5-cm cystic right ovary that contained a 1.0-cm struma ovarii with a 0.4-cm nodule of follicular variant papillary thyroid carcinoma within it. The patient was treated with methimazole and radioiodine ablation of the thyroid. Three months later, a massive myocardial infarction resulted in her death.

The concomitant presence of Graves' disease complicates the management of struma ovarii and raises interesting questions about treatment and prognosis.