is a condition that affects the area between the lungs (mediastinum) which contains the heart, large blood vessels, windpipe (trachea), esophagus, and lymph nodes. People with fibrosing mediastinitis have varying amounts of scar tissue in the mediastinum which may cause problems for the organs located there. For example, some affected people may develop blocked airways that can interfere with lung function. Others may have compressed blood vessels which can slow or prevent blood flow to and from the heart. The exact cause of fibrosing mediastinitis is not fully understood, but it is not inherited. Many cases are linked to a specific type of fungal infection called histoplasmosis. Treatment depends on which structures of the mediastinum are affected, the severity of the scarring and, in some cases, the cause of the condition. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.