Fine-Needle Aspiration Cytology in Diagnosis of Tuberculous Lymphadenitis: Experience From a Tertiary Hospital in Tanzania

Abstract Objectives Tuberculous lymphadenitis is among the common causes of lymphadenopathy in low-resource countries. Data regarding diagnosis of tuberculous lymphadenitis based on fine-needle aspiration cytology of the lymph nodes are scant in our setting. The current study was conducted to determine the usefulness of fine-needle aspiration materials in the diagnosis of Tb lymphadenitis among patients who presented with enlarged lymph nodes. Methods A prospective study was conducted at Muhimbili National Hospital for the duration of 1 year (April 2016 to March 2017). Patients with enlarged lymph nodes were subjected to fine-needle aspiration cytology and smears were stained with Papanicolaou stain as well as Ziehl Nielsen (ZN). Criteria for diagnosing TB on cytology included granulomas, caseous necrosis, and epithelioid cells. All aspirates were subjected to GeneXpert assay for Mycobacterium tuberculosis. All cases diagnosed with TB based on cytological materials were initiated anti-TB. Follow-up of patients was done and response to treatment was used to confirm the diagnosis. Results One hundred sixteen cases were studied. Out of 116 cases of lymph nodes aspirated, 58 cases (50%) were diagnosed as tuberculous lymphadenitis. Females represented the majority of the cases, 31/58 (53%), and the most affected age group was 18 to 35 years. Cytomorphology of TB was found in 40/58 cases (68%) and ZN positivity for acid-fast bacilli (AFB) was found in 14/58 (24%) while Gene Xpert assay was positive in 29/58 (50%) of cases. The response to treatment was 100%. Conclusion Fine-needle aspiration cytology (FNAC) has shown to be simple, safe, and with higher accuracy in diagnosis of tuberculous lymphadenitis based on evaluation of cytomorphology with complementation of ZN stain for AFB in TB endemic areas. The diagnostic accuracy can be further increased by GeneXpert analysis, which can test the drug resistance of the Mycobacterium.