Mycobacterial culture of fine needle aspirate - a useful tool in diagnosing tuberculous lymphadenitis.

A prospective study was undertaken on suspected lymph node TB (LNTB) patients, to evaluate the diagnostic utility of mycobacterial culture of fine needle aspirate (FNA), in comparison with the cytological examination and acid fast staining. Eighty percent of 157 aspirates studied were positive by cytological examination; 18% by ZN smear and 45% were positive by culture. Twelve aspirates which were negative by cytological features yielded positive mycobacterial cultures; four out of these were from HIV positive patients. Our observations suggest that supplementing FNA cytology with mycobacterial culture would increase the sensitivity of diagnosing LNTB; in addition to giving a highly specific diagnosis.