SLE pericardial effusion clinically mimicking hypothyroidism and tuberculosis diagnosed on cytology with LE cells.

The occurrence of lupus erythematosus cells (LE cells) in serous body fluids is extremely uncommon but, when present, is highly specific for systemic lupus erythematosus (SLE). LE cells are commonly reported in pleural and peritoneal effusions but very rarely documented in pericardial effusion. Here, we report a case in which pericardial fluid examination clinched the diagnosis of SLE which was clinically suspected of tuberculosis/hypothyroid effusion by striking presence of LE cells on May-Grünwald Giemsa-stained and Papanicolaou stained smears. Subsequent serologic studies revealed high titers of anti-nuclear antibodies and anti-ds-DNA confirming the diagnosis of SLE. This case highlights the importance of careful examination of pericardial fluid or pleural or peritoneal fluid in the diagnosis of unsuspected cases of SLE in an era wherein "LE cell detection" is considered to be of historic interest.