Mediastinal fibrosis

Given the rarity of mediastinal fibrosis, most reports are retrospective series of cases. Because of the belief by some that mediastinal fibrosis and mediastinal granuloma are one entity, many publications make no attempt to stratify the patients, leading to significant discrepancies in the reported clinical course and prognosis. Clinicopathologic correlations suggest that mediastinal fibrosis is an invasive process that causes impairment of mediastinal structures, whereas mediastinal granuloma is a more benign entity. It is unknown whether mediastinal granuloma progresses to fibrosis. Patients with mediastinal fibrosis present with symptoms related to the invasion of mediastinal structures, most frequently airway obstruction. Occlusion of pulmonary arteries and veins may cause symptoms resembling thromboembolic disease. The most common cause of mediastinal fibrosis is infection with Histoplasma capsulatum. Histopathologic analysis often suggests a prior infection with H. capsulatum, yet cultures are usually negative, arguing against an active infection. Mediastinal fibrosis is often misdiagnosed, compromising treatment, which is limited. Antifungal agents and steroids have minimal value; surgery is technically difficult and associated with a high mortality. Alternatively, surgery for mediastinal granuloma is safe and effective.