The diagnostic efficacy of fine-needle aspiration using cytology and culture in tuberculous lymphadenitis.

OBJECTIVE: To retrospectively assess the diagnostic efficacy of fine-needle aspiration (FNA) using cytological and microbiological examinations in tuberculous lymphadenitis.

METHODS: Patients with tuberculous lymphadenitis treated at St Mary's Hospital, London, between January 2001 and June 2007 were identified. The cytological and microbiological reports of 97 patients were found. The criteria for a definite diagnosis of tuberculous lymphadenitis were based on a compatible clinical history, tuberculin positivity and either an indicative cytological result or positive culture.

RESULTS: In 77 of the 97 (79%) cases, FNA cytology showed evidence of a tuberculous process. In 65 cases, Mycobacterium tuberculosis was cultured from the aspirates, and 54 of these 65 cases showed corresponding cytological evidence of a tuberculous process; 23 cases were diagnosed by cytology but not microbiology, while 11 cases were diagnosed by microbiology but not cytology.

CONCLUSION: Cytological and microbiological results appeared to correlate well, but each also gives an exclusive diagnosis. When combining both modalities, the diagnostic efficacy of FNA rises to 91%. A definitive microbiological diagnosis was achieved in 67% of cases and provided information on drug susceptibility. We conclude that samples should be provided for both cytological and microbiological examination when using FNA to diagnose possible tuberculous lymphadenitis.