Fine Needle Aspiration Cytology for the Diagnosis of Tuberculous Lymphadenitis

Background: Tuberculosis is a major public health problem in India and one of the main causes of lymphadenopathy. However, anti-tubercular treatment cannot be given only on clinical suspicion. Cytomorphology with acid fast staining proves to be a valuable tool in diagnosing these cases. Aim: To assess the role of FNAC in diagnosing tuberculous lymphadenitis and also to study the role of repeat aspiration cytology in patients with strong clinical suspicion of tuberculosis. Research Methodology: FNAC were done by cytopathologist after taking a detailed clinical history regarding duration of swelling, site, size, consistency and mobility. The alcohol fixed smears were stained with Papanicolaou stain, air-dried smears stained with May-Grunwald Giemsa (MGG) and Ziehl-Neelsen (ZN) stain for Acid-Fast Bacilli (AFB). Results: Out of 728 cases with lymphadenopathy of various aetiologies, 264 cases were diagnosed as tuberculous (TB) lymphadenitis. Four cytomorphologic patterns were observed: 1) Epithelioid granulomas with caseous necrosis: 142 cases (53.79%). 2) Epithelioid granulomas without caseous necrosis: 73 cases (27.65%). 3) Necrotising lymphadenitis: 38 cases (14.39%), and 4) Necrotising and suppurative lymphadenitis: 11 cases (4.17%). Ninety two cases were diagnosed as reactive lymphadenitis with activated histiocyte clusters and were advised a repeat aspiration after a course of antibiotics. Out of the 41 cases that turned-up for re-aspiration, 27 cases showed subsequent development of epithelioid granulomas, whereas the others continued to reveal features of reactive lymphadenitis. Conclusion: FNAC is a reliable, rapid and cost-effective, outdoor diagnostic procedure requiring minimal instrumentation and is highly sensitive to diagnose tuberculous lymphadenitis and repeat aspiration, after 3−4 weeks helps in providing the correct diagnosis of early tubercular lesions.