Improved microscopical detection of acid-fast bacilli by the modified bleach method in lymphnode aspirates.
OBJECTIVE
To improve the smear microscopy for detection of acid-fast bacilli (AFB) in fine needle aspiration cytology (FNAC) of lymph node using the bleach method and also to compare this with cytological diagnosis and the conventional Ziehl-Neelsen (ZN) method.


METHODS
In 99 consecutive patients with clinical suspicion of tuberculosis (TB) presenting with lymphadenopathy, FNACs were performed. Smears from the aspirates were processed for routine cytology and the conventional ZN method. The remaining material in the needle hub and/or the syringe was used for the bleach method. The significance of the bleach method over the conventional ZN method and cytology was analyzed using the chi2 test.


RESULTS
Of 99 aspirates, 93 were studied and the remaining six were excluded from the study due to diagnosis of malignancy in 4.04% (4/6) and inadequate aspiration in 2.02% (2/6). Among the 93 aspirates, 33.33% (31/93) were positive for AFB on conventional ZN method, 41.94% (39/93) were indicative of TB on cytology and the smear positivity increased to 63.44% (59/93) on bleach method.


CONCLUSIONS
The bleach method is simple, inexpensive and potent disinfectant, also limiting the risk of laboratory-acquired infections. The implementation of the bleach method clearly improves microscopic detection and can be a useful contribution to routine cytology.
Annam
Vamseedhar
V
Department of Pathology, Sree Siddhartha Medical College, Hospital & Research Center, Tumkur, Karnataka, India. vamseedhar_a@yahoo.com
Karigoudar
Mahesh H
MH
Yelikar
Balasaheb Ramalingappa
BR
D000293:Adolescent; D000328:Adult; D000368:Aged; D001707:Biopsy, Needle / Q000379:methods; D002648:Child; D002675:Child, Preschool; D004202:Disinfectants / Q000494:pharmacology; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000382:microbiology*; D008297:Male; D008853:Microscopy / Q000379:methods; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000166:cytology / Q000302:isolation & purification*; D012973:Sodium Hypochlorite / Q000494:pharmacology; D014376:Tuberculosis / Q000175:diagnosis*; D055815:Young Adult
D004202:Disinfectants; D012973:Sodium Hypochlorite