Application of confocal microscopy for detecting tuberculous lymphadenitis

Tuberculous lymphadenitis, a form of extra-pulmonary tuberculosis, is diagnosed through the detection of Mycobacterium tuberculosis in tissue samples. Lymphadenitis may be caused by both nontuberculous mycobacteria (NTMs) and Mycobacterium tuberculosis complex (MTBC). Here, we highlight the advantage of using a fluorescent dye in combination with Confocal Laser Scanning Microscopy (CLSM) for identifying Mycobacterium tuberculosis in histological sections of lymph node tissue after correlating with Clinical, histopathological, and microbiological findings. CLSM enables the differentiation of non-specific fluorescence from the Mycobacterium tuberculosis fluorescence through the spectral emission method. This method proved effective even in lymph node tissue samples exhibiting weak staining using the Ziehl-Neelsen method. Overall, the integration of fluorescent dye with CLSM visualisation substantially improves bacillary visualisation, facilitates faster processing, and reduces observer fatigue due to the black background.