Objective: To report a case of Riedel's thyroiditis, which was successfully treated with tamoxifen.
Methods: We present the clinical, laboratory, and imaging findings and describe the clinical course of a patient with Riedel's thyroiditis.
Results: A 40-year-old woman presented with hypothyroidism and a large goiter, which was unresponsive to hormone replacement therapy. Magnetic resonance imaging confirmed the presence of an enlarged thyroid gland, more pronounced on the right than on the left. The patient had progressive discomfort attributable to compressive symptoms in the neck. Surgical exploration of the neck disclosed a hard, immobile thyroid mass, which could not be resected because of adherence to surrounding structures. Biopsy of the thyroid and of the muscles of the neck revealed Riedel's thyroiditis. Treatment with tamoxifen, in a dosage of 20 mg twice a day for more than 1(1/2) years, completely resolved the neck mass (substantiated by follow-up magnetic resonance imaging) and relieved the signs and symptoms of compression of the neck.
Conclusion: Tamoxifen treatment is effective in resolving the mass and compression in Riedel's thyroiditis.