ABSTRACT
INTRODUCTION: Systemic nocardiosis is an infectious disease that is rarely associated with mediastinal lymph nodes. CASE REPORT: We report the case of a 72-year-old male patient treated with a high dose of oral corticosteroids for rheumatoid polyarthritis. This patient presented with rapid overall deterioration associated with mediastinal lymph nodes. Endobronchial ultrasound enabled us to establish a diagnosis of systemic nocardiosis. The patient recovered after having received suitable antibiotic treatment for four months. CONCLUSION: This work reports on a rare clinical presentation of systemic nocardiosis associated with mediastinal lymphadenopathies and highlights the key role of endobronchial ultrasound in diagnosing mediastinal lymph nodes, especially in differential diagnosis for lung cancer.