Fibrosing mediastinitis: an unusual cause of pulmonary symptoms

Abstract

Fibrosing mediastinitis (FM), also known as granulomatous or sclerosing mediastinitis, is an uncommon but serious cause of chest symptoms. Due to an infectious or inflammatory challenge, production of collagen occurs in the confined space of the mediastinum. Collagen formation leads to compression of vital structures, resulting in cough, chest pain and dyspnea. The majority of cases of FM occur as a result of prior exposure to Histoplasma capsulatum. The following is a case of a previously healthy young woman who presented with a 3-month history of cough, chest pain and trouble breathing, and was subsequently found to have fibrosing mediastinitis. Fibrosing mediastinitis should be considered in the differential diagnosis of cough, chest pain and dyspnea, primarily when findings such as increased venous pressure are present on physical exam and hilar abnormalities are seen on chest radiograph. Clinical presentation, diagnosis and management of fibrosing mediastinitis are discussed.

Figure 1.

Chest CT with contrast showing mediastinal mass with calcification (arrow). Dilated superior intercostal and accessory hemiazygous veins due to superior vena cava obstruction (arrow head).

Figure 2.

PET-CT Mild FDG uptake, consistent with a benign etiology for the mass.

Figure 3.

Fibrosing mediastinitis trichrome stain, 10X blue stain highlights the collagen bundles and red stain indicates blood vessels.