A Clinicopathological Study of Fine Needle Aspirates of Lymph Nodes from Patients with Suspected Tubercular Lymphadenopathy: Analysis of 640 Cases from a Tertiary Health Care Centre in North India

Abstract

Introduction: Fine needle aspiration cytology (FNAC) of lymph nodes is an out-patient, simple and, quick, cost-effective procedure that helps in the diagnosis of tubercular lymphadenopathy. This technique has high sensitivity and specificity which in addition to the establishment of cytological diagnosis, also helps to perform ancillary tests like ZN staining for AFB Bacilli and GeneXpert MTB/RIF Assay. Aims: To study the clinical and cytopathological features of fine-needle aspirates of lymph nodes from patients with suspected tubercular lymphadenopathy along with the role of ZN staining And GeneXpert assay in diagnosis. Materials and Methods: In this study 1123 patients presenting with lymphadenitis presenting to the cytopathology lab for FNAC of lymph nodes between May 2018 to May 2021 were included. Out of 1123 patients presenting with lymphadenopathies, there were 640 cases of tuberculous lymphadenitis. The clinical and cytopathological findings of these 640 cases were analyzed. Results: Most cases of tubercular lymphadenopathy were of the adult age group (20-59 years) and showed a female predominance. The most commonly involved lymph node was the cervical group. The most common clinical feature observed was cough (68.5%). Among the four cytomorphological patterns observed, maximum cases showed epithelioid cell granuloma with necrosis. Ziehl- Neelsen staining showed overall AFB positivity of 40.3%. Smear showing necrosis without epithelioid cell granuloma showed maximum AFB positivity among the four patterns.GeneXpert MTB/RIF Assay showed an overall detection rate of 84%. Conclusion: FNAC is a simple, cost-effective, outpatient technique with high diagnostic accuracy in cases of tubercular lymphadenopathy which can be coupled by Ziehl Staining for Acid-fast bacilli and GeneXpert MTB/RIF Assay. However, in smear-negative cases, it poses a diagnostic dilemma, thus in a developing country like India with a high prevalence rate of tuberculosis, FNAC coupled with Z.N. staining and new molecular tests like GeneXpert MTB/RIF assay should be included in the first-line investigation in cases with tubercular lymphadenopathy. Key words: Tuberculosis, Fine Needle Aspirate Cytology(FNAC), Necrosis, Epithelioid cells, Cytopathological pattern, Ziehl–Neelsen Staining, GeneXpert Mycobacterium/Rifampicin(MTB/RIF) Assay

Pretracheal tuberculous lymph node: an uncommon differential of a midline neck swelling

“…It is a simple and cost-effective investigative tool. Cytological criteria include the presence of lymphocytes, epithelioid cells, Langhans giant cells, neutrophils, caseous necrotic background (eosinophilic granular material without recognisable cellular elements), and haemorrhage,8 10 as was also reported in our case 11…”

“…Cytological criteria include the presence of lymphocytes, epithelioid cells, Langhans giant cells, neutrophils, caseous necrotic background (eosinophilic granular material without recognisable cellular elements), and haemorrhage, 8 10 as was also reported in our case. 11 Radiological investigation is helpful when TB of the head and neck is suspected; features may be homogeneous or a central area of low attenuation with an enhancing rim or a calcified node. 12 Our patient had a CT feature of necrotic cervical lymphadenopathy of the pretracheal node.…”