FNAC Diagnosis of Lymph Nodes: An Institutional Experience

Introduction Fine needle aspiration cytology is a simple, cost effective, out-patient diagnostic procedure done for palpable lumps in the body. Chronic lymphadenopathy is local manifestation of a systemic disease and Tuberculosis is the most common cause for lymphadenopathy accounting for increased number of Extrapulmonary Tuberculosis in both developing as well as developed countries. Coupling the cytomorphological features with acid fast bacilli, immunocytochemistry, culture and PCR not only increases the diagnostic specificity but also helps in identifying Non-tuberculous mycobacterial infection thereby altering the mode of treatment. Aim and Objective 1. To study the pattern of disease in lymph nodes using FNAC 2. To study the cytomorphological pattern of TB lymphadenitis and 3. To study the diagnostic algorithm used for diagnosis of TB lymphadenitis Material and Methods Retrospective study of lymph nodes aspirated in between January 2012 to July 2013 were included for the study. Results Fifteen of 65 cases were inadequate for opinion after the aspiration, so excluded from the study. TB was the most common cause for lymphadenopathy in the present study followed by reactive pattern and metastatic deposits. TB lymphadenitis was common among adolescents and young adults, whereas metastatic deposits were common among elderly as usual. Most common cytomorphological pattern observed was granulomatous lymphadenitis with necrosis, followed by granulomatous lymphadenitis without necrosis and only necrotic material. Acid fast bacilli were identified in only two cases. Discussion Common diagnostic algorithm for cytologic diagnosis is used in present study like in other studies. Acid fast bacilli were detected in only two cases. But studies have demonstrated mycobacterial antigen in necrotic debris where it was negative for acid fast bacilli. Conclusion Procuring the aspirate material for immunocytochemistry, culture, PCR in case of suspected Mycobacterial infection, not only increases the diagnostic specificity but also helps in differentiating tuberculous from non-tuberculous lymphadenitis. It is also a useful tool in primary diagnosis and classification of lymphoma by providing material for ancillary studies. But immunocytochemistry and culture are not done in the present study, which would have improved the diagnostic accuracy.