peer reviewedFibrosing mediastinitis is a rare condition characterized by an excessive growth of dense fibrous tissue within the mediastinum. The etiology of the disease is most often a fungal infection and may in some cases be idiopathic. We present the case of a patient with chronic obstructive pulmonary disease (COPD) suffering from fibrosing mediastinitis of undetermined origin and in whom the diagnosis was established by histopathological analysis after mediastinoscopy