Unclassified connective tissue disease presenting as cardiac tamponade: a case report.

This report describes a case of cardiac tamponade as the initial manifestation of unclassified connective tissue disease (UCTD). A 68-year-old Japanese woman was admitted to hospital because of dyspnea and edema. She had undergone a radical left mastectomy for the treatment of breast cancer 18 years before. On admission, bilateral leg edema, hepatomegaly, and a paradoxical pulse were noted on physical examination. The erythrocyte sedimentation rate was elevated and the C-reactive protein was 2.8 mg/dl. Antinuclear antibodies and anti-SS-A/Ro antibodies were present. The scl-70 and anticentromere antibodies were elevated. Chest radiography showed cardiomegaly. Echocardiography revealed a large pericardial effusion, but the pericardial fluid did not contain malignant cells or bacteria. She did not meet the diagnostic criteria for any known connective tissue diseases, so was diagnosed with cardiac tamponade due to UCTD. Prednisolone (30 mg/day) was administered, which resulted in a gradual resolution of the pericardial effusion. Although connective tissue diseases are known to cause pericardial effusion, cardiac tamponade as the initial manifestation of the disease in the absence of other symptoms is quite rare.