Role of modified bleach method in staining of acid-fast bacilli in lymph node aspirates.
OBJECTIVE
To correlate acid-fast bacilli (AFB) positivity with cytomorphologic patterns of tuberculous lymphadenitis and evaluate bleach concentration method in diagnosing lymph node tuberculosis compared to Ziehl-Neelsen (ZN) method.


METHODS
One hundred cases of tuberculous lymphadenitis diagnosed by fine needle aspiration cytology (FNAC) were analyzed and classified into 6 cytomorphologic patterns and correlated with bacillary load using routine and modified bleach methods of ZN staining. Smears were graded for AFB positivity. Sensitivity of routine ZN and modified bleach concentration was compared.


RESULTS
The classic cytomorphologic pattern of tuberculosis showing epithelioid granulomas, Langerhans giant cells and caseous necrosis was seen in 23% of cases. Routine ZN staining detected AFB in 27% of cases and the modified bleach method in 72%. In 58 cases the modified bleach method had a higher grade of AFB positivity than the routine method. The modified bleach method did not miss any AFB positivity detected on routine ZN staining.


CONCLUSIONS
The modified bleach method demonstrated AFB positivity in 72% of cases. AFB positivity grade was much higher than with routine ZN staining, making bacilli easily visible, with shorter screening time. The modified bleach method is inexpensive, easily performed and more sensitive and safe than routine ZN staining.
Gangane
Nitin
N
Department of Pathology, Mahatma Gandhi Institute of Medical Sciences, Sevagram 442102, Wardha, Maharashtra, India. nitingangane@rediffmail.com
Anshu
Singh
Ranbeer
R
D044963:Biopsy, Fine-Needle; D006801:Humans; D006997:Hypochlorous Acid; D008198:Lymph Nodes / Q000382:microbiology* / Q000473:pathology; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012394:Rosaniline Dyes; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods*; D014388:Tuberculosis, Lymph Node / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology
D012394:Rosaniline Dyes; D006997:Hypochlorous Acid