Tuberculous lymphadenitis: correlation of cellular components and necrosis in lymph-node aspirate with A.F.B. positivity and bacillary count.

Cytomorphologic features of tuberculous lymphadenitis cases as observed in lymph-node aspirates were analysed and correlated with AFB positivity and bacillary count. Cytologic features were categorized under three major groups, viz. epithelioid granuloma without necrosis, epithelioid granuloma with necrosis and necrosis without epithelioid granulomas. These three major groups showed a distinct trend in respect of their cellular constituents. While cases with appreciable lymphocytic and multinucleated giant cells component showed a significant decreasing trend, cases with neutrophilic infiltration showed an increasing trend (P less than 0.001). In the above three groups, 9.1 percent, 64.7 percent and 77.4 percent respectively showed AFB positivity, the difference being highly significant (P less than 0.001). All 14 cases with very high bacillary count (greater than 50 bacilli per 500 oil immersion field) were associated with necrosis and 71.4% of them neutrophilic infiltration. A univariate analysis revealed that in presence of lymphocytes, epithelioid cells and Langhan's giant cells, AFB positivity was significantly lower while the picture was just the reverse in presence of necrosis and neutrophilic infiltration (P less than 0.001). The odd's rations for all these variables were highly significant (P less than 0.001). However, a multivariate regression analysis revealed that necrosis was the only independent contributing factor towards AFB positivity.