An Unusual Case of Tuberculous Lymphadenitis and Comparison of Various Methods for Diagnosis of Tuberculous Lymphadenitis

Tuberculous Lymphadenitis and TBNAAT

Abstract

Although tuberculous lymphadenitis (TBLN) is extremely common in India, sometimes it may pose a diagnostic dilemma even after multimodality testing. This case report is about a patient who had undergone multiple fine needle aspirations (FNAC), Ziehl-Neelsen staining of aspirate, GeneXpert Nucleic acid amplification test (TBNAAT), biopsy and immunohistochemistry before arriving at a provisional diagnosis by hematoxylin-eosin staining of additional deeper sections. Additional information obtained by TBNAAT is whether the isolated strain is sensitive to Rifampicin. Emergence of multidrug resistance tuberculosis (resistance to rifampicin and INH) and extensively drug resistant strains implying resistance to fluoroquinolones and second-line injectable drugs can be a huge problem in the management of the disease. She is now under treatment and follow up. This case report highlights that caseation necrosis on FNAC even in the absence of acid-fast bacilli and a negative TBNAAT is strongly suggestive of tuberculous aetiology and may be used for initiating definitive treatment. A comparison of results of ZN stain of aspirate with TBNAAT for 22 cases of clinically suspected TBLN is also brought out.