First and only manifestation of Hashimoto's disease: pericardial tamponade.

Pericardial effusion in hypothyroidism is a common finding, but an effusion which causes cardiac tamponade is a rarity. A 39-year-old man without previous medical history presented with progressive shortness of breath. Transthoracic echocardiography revealed massive pericardial effusion with tamponade findings. Thyroid function analysis showed raised thyroid-stimulating hormone associated with a severe decrease of free thyroxine and triiodothyronine. Antithyroglobulin and antithyroperoxidase antibodies were significantly high. The echocardiography-guided pericardiocentesis was followed by thyroid replacement therapy with the diagnosis of Hashimoto's disease. We report a case of pericardial tamponade as the first and only manifestation of Hashimoto's disease.