Cytodiagnosis of tuberculous lymphadenitis. A correlative study with microbiologic examination

One hundred two of 272 cases of cytodiagnosis of tuberculous lymphadenitis were subjected to mycobacterial examination by Ziehl-Neelsen staining on direct and concentration smears and by culture. Cytomorphologically the cases were categorized into four types: 1, predominantly necrotic material; 2, typical caseating epithelioid cell granulomas and giant cell formation; 3, only noncaseating epithelioid cell granulomas with or without giant cells; and 4, doubtful presence of epithelioid cells. Ziehl-Neelsen staining for acid-fast bacilli (AFB) was positive in 25% in direct smears, 26.5% in concentration smears and 29.5% in both combined. The cultures for mycobacteria were positive in 49%; combined smear and culture positivity was found in 56.9%. Maximum culture positivity was seen in cases with type 1 smears (56.9%) followed by types 2 (44%) and 3 (40%). The percentage of AFB positivity was similar in type 1 and type 2 smears (32.2% and 30%, respectively); however, AFB were present in large numbers in type 1 smears as compared to type 2 and 3 smears. In type 3 smears AFB positivity was found in 20% of cases. Cases with type 4 smears were negative for AFB in smears and culture. In eight cases (7.8%) the smears were positive for AFB, whereas the cultures were negative, indicating that negative culture examination still does not exclude the possibility of tuberculosis. However, culture is essential to a characterization and determination of drug sensitivity.