Diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration for isolated mediastinal lymphadenopathy in a tuberculosis-endemic region: first study from Northeast India

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique for evaluating mediastinal lymphadenopathy, especially in tuberculosis-endemic regions where differentiating infectious, inflammatory, and malignant causes remains challenging. This retrospective study aimed to assess the diagnostic yield of EBUS-TBNA in patients from the northeastern states of India, a region with a high burden of tuberculosis and limited diagnostic resources. A total of 74 patients with isolated mediastinal lymphadenopathy (IML) who underwent EBUS-TBNA between 2021 and 2023 at a tertiary care hospital in Meghalaya were included. The final diagnosis was based on histology, cartridge-based nucleic acid amplification test (CBNAAT), culture, and clinical-radiological follow-up for up to 1 year in inconclusive cases. EBUS-TBNA achieved an overall diagnostic yield of 78.6%. The most common diagnosis was malignancy (36.5%), followed by tuberculosis (23%), reactive lymphadenitis (13.5%), and sarcoidosis (5.4%). CBNAAT was positive in 47.1% of tuberculosis cases, with multidrug resistance detected in 11.7%. The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 90.6%, 100%, 100%, and 62.5%, respectively. To conclude, EBUS-TBNA is a safe, highly sensitive, and cost-effective diagnostic modality for IML in tuberculosis-endemic regions. The addition of CBNAAT enhances diagnostic precision and enables early detection of drug resistance. The study also highlights an emerging trend of higher malignancy rates in the Northeastern Indian population, underscoring the need for comprehensive evaluation in all cases of IML.