Discussion of Fibrosing mediastinitis
- Fibrosing mediastinitis is a rare benign disorder caused by proliferation of acellular collagen and fibrous tissue within the mediastinum.
- Although many cases are idiopathic, many cases in the United States are thought to be caused by an abnormal immunologic response to Histoplasma capsulatum infection.
- Affected patients are typically young and present with signs and symptoms of obstruction or compression of the superior vena cava, pulmonary veins or arteries, central airways, or esophagus.
- There may be two types of fibrosing mediastinitis: focal and diffuse.
- The focal type usually manifests on computed tomographic or magnetic resonance images as a localized, calcified mass in the paratracheal or subcarinal regions of the mediastinum or in the pulmonary hila.
- The diffuse type manifests on CT or MR images as a diffusely infiltrating, often noncalcified mass that affects multiple mediastinal compartments.
- Fibrosing mediastinitis often has an unpredictable course, with both spontaneous remission or exacerbation of symptoms being reported.
- There are three possible avenues for treatment: systemic antifungal or corticosteroid treatment, surgical resection, and local therapy for complications.
 Imaging Findings for Fibrosing mediastinitis
- Fibrosing mediastinitis typically manifests on CT scans as an infiltrative mass of soft-tissue attenuation that obliterates normal mediastinal fat planes and encases or invades adjacent structures.
- Fibrosing mediastinitis most commonly affects the middle mediastinal compartment, including both the right and left paratracheal and subcarinal regions as well as the hila.
- The anterior and posterior mediastinum are much less frequently involved.
- Fibrosing mediastinitis typically manifests on T1-weighted MR images as a heterogeneous, infiltrative mass of intermediate signal intensity.
- Its appearance on T2-weighted MR images is more variable; regions of both increased and markedly decreased signal intensity are frequently seen in the same lesion.
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 External Links
 References for Fibrosing mediastinitis
- Santiago E. Rossi, H. Page McAdams, Melissa L. Rosado-de-Christenson, Teri J. Franks, and Jeffrey R. Galvin. Fibrosing Mediastinitis. RadioGraphics 2001 21: 737-757.