A case of Riedel's thyroiditis with pleural and pericardial effusions.

Riedel's thyroiditis (RT) is a rare type of chronic thyroiditis of unproven etiology and definite treatment. It can be associated with retroperitoneal, mediastinal, orbital, and hepatic fibrosis. Symptoms arise mainly due to compression of neighboring structures. Surgery is usually required for a definite diagnosis and decompression to relieve the symptoms. Glucocorticoids and tamoxifen are commonly used agents for the pharmacotherapy. We hereby describe the development of pleural and pericardial effusions during the clinical course of an RT case. A 39-year-old woman suffering from neck compression symptoms was admitted to the hospital. After a decompression isthmectomy, RT was diagnosed. She responded well to glucocorticoid therapy after surgery. However, symptoms reoccurred shortly after glucocorticoid withdrawal and the disease process extended to the mediastinum. Tamoxifen was started and the neck and mediastinal mass regressed and her symptoms disappeared considerably for more than 6 months. However, she was readmitted with severe dyspnea and chest pain. Further investigation revealed an exudative pleural and pericardial effusion and mediastinal enlargement. A thorough evaluation of the patient's effusions did not disclose any specific etiological insult. The patient was symptom-free with a considerable reduction of the soft tissue mass and no effusions, and treated successfully with colchicine, azathioprine, and glucocorticoids. To the best of our knowledge, this is the first case reported in the literature as an RT presenting with pleuropericardial effusions.