Steroid versus antituberculosis treatment: Minimizing side effects through accurate diagnosis – The role of endobronchial ultrasound in differentiating pulmonary tuberculosis from sarcoidosis

Background: Sarcoidosis is a multisystem granulomatous disorder of unknown etiology, histologically defined by noncaseating granulomas. In tuberculosis (TB)-endemic regions like India, it is frequently misdiagnosed as TB due to overlapping clinical and radiological features. Such misdiagnosis may lead to inappropriate treatment, with potentially harmful outcomes. Aims and Objectives:To highlight the clinical utility of endobronchial ultrasound (EBUS)-guided lymph node sampling in differentiating sarcoidosis from pulmonary tuberculosis, and to emphasize the importance of accurate diagnosis in guiding appropriate treatment and minimizing adverse effects. Materials and Methods: This case series includes seven patients who presented with symptoms such as nonproductive cough, low-grade fever, and weight loss. All patients underwent contrast-enhanced computed tomography (CT) of the chest, which revealed multiple enlarged mediastinal lymph nodes. Three patients were previously started on empirical anti-tuberculosis treatment (ATT) based on clinicoradiological findings. EBUS-guided fine-needle aspiration (FNA) and biopsies were performed under general anesthesia. Histopathological examination was carried out along with GeneXpert testing for Mycobacterium tuberculosis and serum angiotensin-converting enzyme (ACE) level estimation. Results: Histopathology revealed nonnecrotizing granulomas composed of epithelioid cells and histiocytes in all cases, consistent with sarcoidosis. Serum ACE levels were elevated, and GeneXpert results were negative for TB in all patients. Based on these findings, ATT was discontinued in the three affected patients, and all seven were started on immunosuppressive therapy. Significant clinical improvement was noted on follow-up. Conclusion: In TB-endemic settings, distinguishing sarcoidosis from tuberculosis remains a diagnostic challenge. EBUS facilitates safe and accurate sampling of mediastinal lymph nodes, enabling histological confirmation. Correct diagnosis is crucial, as initiating immunosuppressants in TB can be hazardous, while ATT is ineffective in sarcoidosis. This case series underscores the pivotal role of EBUS in preventing misdiagnosis and guiding targeted therapy in granulomatous lung diseases.