Cytopathological Pattern of Tubercular Lymphadenopathy on FNAC: Analysis of 550 Consecutive Cases

Background: Fine needle aspiration cytology (FNAC) of lymph nodes is a simple, cost effective, out-patient procedure used for diagnosis of various causes of lymphadenopathies. In tuberculous lymphadenitis, it not only used for the cytological diagnosis but also used for other ancillary testing such as Ziehl-Neelsen staining and AFB Culture. Aims: Our study was designed to evaluate the cytopathological pattern of FNAC aspirate of patients presenting with lymphadenopathy with special reference to tuberculous lymphadenopathy. Materials and Methods: In this study all the patients referred to the cytopathology lab for FNAC of lymph nodes between January 2011 to June, 2013 were included. Out of 1050 patients presenting with lymphadenopathies, there were 550 cases of tuberculous lymphadenitis. The cytopathological findings of these 550 cases were analyzed. Results: A female preponderance was noted in our study with maximum incidence in the 3rd decade. Cervical lymph nodes were the most common nodes to be involved. Gross examination of aspirate showed maximum cases (74.5.2%) of whitish material. Among the four cytological patterns on FNAC, maximum cases demonstrated caseous necrotic material with degenerated inflammatory cells. Ziehl-Neelsen staining showed overall AFB positivity of 44.54%. Maximum AFB positivity was seen in cases having caseous necrosis only. Conclusion: FNAC is a simple, cost effective technique with high degree of accuracy in diagnosing Tubercular Lymphadenitis. Despite certain limitations and pitfalls, FNAC coupled with Ziehl-Neelson staining should be the 1st line investigation in cases with lymphadenopaty, in a developing country with high prevalence rate of tuberculosis.