Mycobacterial cervical adenitis in Auckland: diagnosis by fine needle aspirate

Aims. 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. Method. 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. Results. 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. Conclusions. (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 he 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.