Fine-needle Aspiration Cytology in Tuberculous Lymphadenitis: A Study of 200 Cases of Superficial Lymphadenopathy

Background: In developing countries, tuberculous lymphadenitis is one of the most common causes of lymphadenopathy. Moreover, India is one of them. Patients are presenting with the only lymph node enlargement, with or without any symptoms. However, antitubercular treatment cannot be given only on clinical suspicion. Cytomorphology with acid-fast staining proves to be a valuable tool in diagnosing these cases. Aims: The aim is to study the advantages, limitations, and utility of fine-needle aspiration cytology (FNAC) and various cytomorphological presentations inreference to Ziehl-Neelsen (Z-N) staining in tuberculous lymphadenitis. Material and Methods: In a study period of January 2015–December 2016, in Pathology Department, GMERS Medical College, Ahmedabad, 200 cases in case of 300 patients with enlarged superficial lymph nodes, clinically suspected to be tuberculous were subjected to cytological evaluation with Hematoxylin and Eosin, Giemsa and Z-N stained smears. In addition, the social status and economic profile of these patients with the clinical presentation were also studied. Results: Incidence of tuberculous lymphadenitis was 63%. Overall acid-fast bacilli (AFB) positivity was 65.0%. Only necrosis without epithelioid cell granulomas was the most common cytological picture and that showed highest AFB positivity also. Threefourth of the patients presented in the second to fourth decades of life. Cervical region was the most common site of involvement with solitary lymphadenopathy as the most common presentation in contrast to matted lymph nodes as reported by others. Conclusions: FNAC is a safe, cheap procedure requiring minimal instrumentation and is highly sensitive to diagnose tuberculous lymphadenitis. The sensitivity can be further increased by complementing cytomorphology with acid-fast staining. In acid-fast staining negative cases, the yield of AFB positivity can be increased by doing Z-N staining on second smear or decolorized smear revealing necrosis or by repeat aspiration. Microbiological assessment should also be done in such cases.