Cytomorphology versus conventional microbiological tests in the diagnosis of tuberculous lymphadenitis

ABSTRACT

To determine the accuracy of Fine Needle Aspiration Cytology [FNAC] in the diagnosis of tuberculous lymphadenitis. Comparative cross-sectional study. Department of Pathology, Khalifa Gul Nawaz Teaching Hospital [KGNTH], Bannu, from September 2012 to March 2013. FNAC of enlarged lymph nodes was performed in the Department of Pathology, KGNTH, Bannu. Smears of the aspirates were examined under light microscope after staining with Haematoxylin and Eosin [H and E] stains. In cases of chronic lymphadenitis, the smears were stained with Ziehl-Neelsen [ZN] stain for Acid Fast Bacilli [AFB]. If no AFB was visualized, the aspirate was subjected to culture on Lowenstein Jensen [LJ] medium for yield of AFB. The results were analyzed by Microsoft Excel software. Chronic granulomatous lymphadenitis was found in 110 [46.81%] out of 235 cases. AFB were seen in aspirates of 43/110 [39.09%] cases by direct microscopy. Among the remaining 67 aspirates subjected to LJ medium, only 07 [10.45%] yielded growth of AFB. Smears of 4/15 [3.6%], 13/47 [11.7%] and 33/48 [29.7%] cases with haemorrhagic, inflammatory and caseous background respectively, were confirmed by conventional microbiologic tests. Out of 125 nongranulomatous lymphadenitis cases only 05 were confirmed to be due to tuberculosis by direct microscopy while culture was not positive in any case. Thus accuracy of FNAC was 72.34%.FNAC has a good accuracy in diagnosing tuberculous lymphadenopathy