Brief observation

Detection and follow-up of mediastinal lymph node enlargement in tuberculous pericardial effusions using computed tomography

Methods

We studied patients with large pericardial effusions (sum of echo-free space >20 mm) or who were suspected to have tamponade using standard echocardiographic criteria (6); such patients are transferred routinely to our center. Urgent or deferred pericardial aspiration and biopsy were performed (7); biopsy was not attempted in the postsurgical patients. Pericardial fluid was sent for cytology, routine biochemical analysis, and culture for tuberculosis. Biopsy specimens were processed for culture

Results

The 41 patients, of whom 21 were men, were seen between 1996 and 2001 (Table 1). Their mean (± SD) age was 41 ± 18 years. Twenty-two (54%) had tuberculosis, 6 (15%) had postcardiotomy syndrome, and 13 (32%) had viral/idiopathic pericarditis. None were seropositive for the human immunodeficiency virus.

The ages of the patients (16 men, 6 women) with tuberculous effusions ranged from 21 to 70 years (mean, 36 ± 13 years). A tuberculin skin test was performed in 18 of these patients. The induration

Discussion

Most often, pericardial tuberculosis is due to breakdown of infected mediastinal nodes directly into the pericardium 1, 13. In this study, only the 22 patients with tuberculous pericardial effusions had mediastinal node enlargement. After treatment, these enlarged nodes disappeared or regressed; by contrast, normal nodes do not change size (14). The CT scans were not repeated at fixed intervals, so we do not know how long it takes for enlarged nodes to regress. However, the specificity of lymph

Acknowledgements

The authors are grateful to Ajitha Nair for statistical analysis and Suresh Nair for help with the manuscript preparation.