Analysis of Fine Needle Non Aspiration Cytology for the Diagnosis of Cervical Lymph Node Tuberculosis: A Cross-sectional Study

Abstract

Introduction: Conventionally, excision biopsy is performed for the diagnosis of Lymph Node Tuberculosis (LNTB). Comparatively, Fine Needle Non Aspiration Cytology (FNNAC) is a simple, reliable, inexpensive, painless, less invasive, outpatient procedure for the diagnosis of peripheral LNTB and is recommended as the first diagnostic technique for this condition. Fine Needle Non Aspiration Cytology (FNNAC), i.e., fine needle sampling without aspiration, is relatively painless, less traumatic and more patient-friendly compared to FNAC. Although FNNAC is easy to perform, it is not routinely practiced. Aim: To evaluate the results of FNNAC in cervical lymphadenopathy and determine the various cytomorphological presentations in cervical LNTB. Materials and Methods: This institutional-based, cross-sectional study was conducted at the Department of Respiratory Medicine, Princess Krishnajammanni TB and Chest Diseases Hospital (PKTB and CDH), Mysore Medical College and Research Institute (MMC and RI) in Mysuru, from January 2019 to September 2022 on presumptive cervical LNTB patients who underwent FNNAC followed by an excision biopsy of the same Lymph Node (LN). The sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and accuracy of FNNAC for diagnosing LNTB were estimated. Results: A total of 415 subjects were studied. The sensitivity, specificity, PPV and NPV rates of FNNAC for Tuberculosis (TB) were 97.92%, 100%, 100% and 99.3%, respectively, with an accuracy of 99.4%. A total of 36 samples (8.7%) were considered Non Diagnostic (ND). Among these 36 ND samples, 31 were of benign origin (4 were TB), while the remaining five ND samples were of malignant origin. Conclusion: The present study reveals that TB is currently the most common cause of cervical lymphadenopathy, with other common causes being malignant metastasis and reactive lymphadenitis. FNNAC is highly accurate in the diagnosis of LNTB. Therefore, FNNAC is a simple, safe, economical, reliable and accurate method for diagnosing cervical LNTB.

Keywords

• fine needle aspiration
• mycobacterium tuberculosis
• tuberculous cervical lymphadenopathy