Mycobacterial cervical adenitis in Auckland: diagnosis by fine needle aspirate

To evaluate the role of fine needle aspiration (FNA) in the diagnosis of tuberculous and non-tuberculous mycobacterial cervical adenitis in Auckland, and to examine the demography of these conditions.

We reviewed the medical records of cases of mycobacterial adenitis in the Auckland region between 1991-1994. Cases were identified by cross-checking the reference mycobacteriology laboratory records, all hospital cytology reports from cases who had an FNA taken from the neck region and hospital discharge diagnosis databases.

Twenty-two cases of M tuberculosis adenitis, and 13 of M avium adenitis were identified. No FNAs were smear positive for mycobacteria. The FNA from 6/18 (33%) cases of M tuberculosis adenitis and from 4/6 (66%) M avium adenitis cases were culture positive. Bacteriological confirmation was obtained (by various methods) in 72% of tuberculous and in 100% of M avium adenitis cases. The clinical picture was different for the two organisms: tuberculous adenitis occurred mainly in caucasian adults, while M avium adenitis cases were predominantly caucasian children. None of the confirmed cases of tuberculous adenitis demonstrated drug resistance to standard anti-tuberculous agents.

(1) Clinicians should more consistently include mycobacterial tests when investigating neck lumps. (2) FNA is not a reliable diagnostic test for mycobacterial cervical adenitis in New Zealand. Here, FNA should only be regarded as a screening test for mycobacterial adenitis. If anti-tuberculous treatment is required before it is known whether FNA has provided a positive culture, excision biopsy should first be performed to identify the mycobacterium and its susceptibility pattern.