How does clinical diagnosis of mycobacterial adenitis correlate with histological findings?

To describe and compare histopathological findings with clinical criteria in diagnosis of TB adenitis.

Lymph node biopsies were obtained from 213 patients. Specimens were processed for culture and histopathologic examination, using standard methods. One hundred blocks with good preservation of tissue morphology were selected for detailed histological examination.

About 75% of 213 patients had granulomas. In the remaining 25%, neither histopathological nor microbiological evidence of mycobacterial disease was found. Of 100 blocks selected for detailed examination, 79 blocks had granulomatous changes. The granulomas were well organised in 24%, mixed in 33%, and poorly organised in 43%. Langhans giant cells and acid-fast bacilli were observed in 88.6% and 21.5% of the 79 blocks, respectively. Cultured specimens were positive in about 10% of 79 biopsy specimens.

Histological evidence of mycobacterial disease was only found in three quarters of patients that were clinically diagnosed and started on empirical treatment for tuberculous adenitis. Neither histological nor mycobacteriological evidence was found in a quarter of the patients who were already on treatment for TB, basing on clinical criteria. These findings call for new research on simple diagnostic tools for patients who seek care for s ymptoms of extra-pulmonary TB.