Cytomorphological Patterns in the Diagnosis of Tuberculous Lymphadenitis

The reliable diagnosis of tuberculous lymphadenitis by FNAC has important implications in a developing country like India. The aim is to study various cytomorphological patterns seen in tuberculous lymphadenitis and their correlation with AFB positivity. Fine needle aspiration cytology (FNAC) was performed on three hundred and twenty two patients with lymphadenopathy referred to the cytopathology section of pathology department, Sri Guru Ramdas Institute if Medical sciences and research Amritsar from August 2010 to July 2012. The patients with cytological diagnosis of tuberculous lymphadenitis were followed for their response to antitubercular treatment. A total of 322 FNACs were performed on patients with lymphnode lesions; out of which the most common (119) cytological diagnosis was tuberculous lymphadenitis. The most common pattern observed was (group II) presence of epitheloid granuloma with caseation necrosis which was seen in about half (50.5%) of the cases followed by smears with caseation necrosis only (group III) (27.7%) and smears with epitheloid granulomas only (group I) (21.8%).The overall AFB positivity was seen in 19.3% cases of tuberculous lymphadenitis. Maximum (30.3%) AFB positivity was seen in smears (group III) with only necrotic debris without granuloma and was least in group I (7.6%).While comparing Group I smears with that of group III using Fisher's exact test, the difference in AFB positivity between the smears was statistically significant as the two-tailed p value was 0.0496. Thus FNAC is safe, easy, quick reliable as well as conclusive for the diagnosis of tuberculous lymphadenitis when done along with Zeihl Neelsen stain for acid fast bacilli.