Role of endoscopic ultrasound guided fine needle aspiration (EUS-FNA) and Gene Xpert

Abstract

Background

Mediastinal tubercular lymphadenitis is form of extrapulmonary tuberculosis [EPTB]. Clinical presentations are non-specific and diagnosis remains great clinical challenge. Microbiological and or histopathological evidences need to be present in order make diagnosis secure before initiation of anti-tubercular therapy (ATT). Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) provides tissue samples and aids management of this difficult to diagnosed entity. Current study describe role of EUS-FNA and Gene Xpert (GXP) in mediastinal tubercular lymphadenitis.

Methods

Retrospective analysis of 72 patients with mediastinal lymphadenopathy who underwent EUS-FNA were carried out. Linear echoendoscope was used for evaluation mediastinum. EUS echo features of LNs were studied. Twenty two-G needle used was for aspiration tissue sample from pathologic lymph nodes (LNs). FNA samples were analysed by cytology, Acid-Fast Bacilli (AFB) staining and GXP study. All procedures were uneventful without any complications.

Results

Forty two patients were diagnosed as tuberculosis (TB) following first EUS-FNA setting. Six patients underwent repeat EUS-FNA procedure following which another 3 were diagnosed as TB while remaining 3 started on empirical ATT based on additional supportive evidences. Forty five patients showed granulomatous inflammation on cytological analysis, AFB positivity noted in 16 (33.33%) patients while GXP in 26 (57.78%) patients. Rifampicin resistance detected in 3 ((6.25%) patients. All patients were followed clinico-radiologically for response to treatment.

Conclusion

Tuberculous lymphadenitis is the most common cause of mediastinal lymphadenopathy in TB endemic countries. EUS-FNA provides microbiological and histopathological/cytological evidences in this difficult to diagnosed EPTB and thereby avoids empirical ATT.