Fibrosing mediastinitis 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
NIG GARD
https://rarediseases.info.nih.gov/diseases/8337/fibrosing-mediastinitis2014

The signs and symptoms of fibrosing mediastinitis depend on which structures of the mediastinum are affected (i.e. the heart, large blood vessels, windpipe, esophagus, and lymph nodes) and the severity of the scarring. Some people with this condition have only a single mass of scar tissue while others develop more extensive scarring that affects the entire mediastinum and may even extend into the neck or lungs. Many symptoms of fibrosing mediastinitis arise when the esophagus, blood vessels and/or airways become blocked or compressed. Signs of these problems may include Cough, Shortness of breath, Recurrent lung infection, Hemoptysis, Pleuritic chest pain, Difficulty swallowing, and Cor pulmonale
GARD
https://rarediseases.info.nih.gov/diseases/8337/fibrosing-mediastinitis2014

“Fibrosing mediastinitis (FM) is a rare but potentially life-threatening proliferation of dense infiltrative fibrous tissue in the mediastinum that causes compression or obstruction of hilar or mediastinal organs. Arterial, venous and aerodigestive tract involvement is at the origin of symptoms and influences prognosis. The non-specific clinical presentation includes cough, dyspnea, recurrent pneumonia, hemoptysis, or pleuritic pain. The main accepted hypothesis is that the origin of this proliferation is secondary to an abnormal immunologic reaction.”
CT features of fibrosing mediastinitis,
Alexandre Garin et al.
Diagnostic and Interventional Imaging, 2021 (in press)

”FM (also known as sclerosing mediastinitis or mediastinal fibrosis), is usually divided into two sub entities that are granulomatous fibrosing mediastinitis (GFM) and non-granulomatous fibrosing mediastinitis (NGFM). GFM represents 80 to 90% of all FMs. GFM is usually considered as an abnormal immunologic response following an infectious disease, mainly histoplasmosis and tuberculosis. FM has also been described after fungal infection such as blastomycosis, mucormycosis, or cryptococcosis.”
CT features of fibrosing mediastinitis,
Alexandre Garin et al.
Diagnostic and Interventional Imaging, 2021 (in press)

“On imaging, the fibrous proliferation is typically associated with stippled or dense localized calcifications and mainly involves the right paratracheal region, the subcarinal region and the hila, as observed in our series. The less common non-granulomatous subtype of FM, NGFM, also called diffuse or idiopathic FM, accounts for 10% to 20% of FMs. The infiltration involves multiple mediastinal compartments and the pulmonary hila, typically without calcifications. It may be associated with extra-thoracic locations, especially retroperitoneal fibrosis, sclerosing cholangitis or autoimmune pancreatitis or observed as a complication of autoimmune diseases, previous radiation therapy or treatment with methysergide.”
CT features of fibrosing mediastinitis,
Alexandre Garin et al.
Diagnostic and Interventional Imaging, 2021 (in press)

“In this rare vascular developmental anomaly, the left pulmonary artery arises from the posterior aspect of the right pulmonary artery and passes between the trachea and esophagus to reach the left hilum. The left pulmonary artery thus forms a sling around the distal trachea and the proximal right main bronchus.”
Congenital and Acquired Pulmonary Artery Anomalies in the Adult: Radiologic Overview
Castañer E et al.
RadioGraphics 2006 26:2, 349-371

“Those affected by pulmonary artery sling may be classified generally into two groups: one with a normal bronchial pattern and the other with one or more malformations of the bronchotracheal tree (eg, stenosis of a long segment of the trachea or absence of the pars membranacea) as well as cardiovascular abnormalities. In the latter group, mortality and morbidity are high during infancy.The former group includes very few asymptomatic adults. In asymptomatic cases, a pulmonary artery sling may mimic a mediastinal mass on chest radiographs . CT and magnetic resonance (MR) imaging may be used to establish the diagnosis with certainty.”
Congenital and Acquired Pulmonary Artery Anomalies in the Adult: Radiologic Overview
Castañer E et al.
RadioGraphics 2006 26:2, 349-371