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Genetic and Rare Diseases Information Center (GARD)

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Fibrosing mediastinitis


Other Names for this Disease

  • Idiopathic mediastinal fibrosis
  • Mediastinal fibrosis
  • Sclerosing mediastinitis
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

Unknowingly I contracted histoplasmosis related fibrosing mediastinitis in my youth. The calcium scarring has asymptomatically over-grown my superior vena cava completely occluding it. Can I become re-infected by another encounter with H. capsulatum fungus? Are my prodigy at higher risk of contracting fibrosing mediastinitis? Is there a genetic component?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is fibrosing mediastinitis?

Fibrosing mediastinitis refers to scarring in the chest that can entrap the esophagus, the heart, the lymph nodes, and the major blood vessels that carry blood to and from the heart.[1] The “mediastinum” refers specifically to the area between the lungs. The scarring may involve a single mass or be diffusely spread throughout the cavity.  In rare cases, fibrosing mediastinitis may extend into the soft tissues of the neck, the back of the chest, and into the lung.[2]
Last updated: 4/23/2010

What are the signs and symptoms of fibrosing mediastinitis?

Early signs and symptoms of fibrosing mediastinits relate to blockages of structures in the mediastinum (e.g., superior vena cava, central pulmonary veins) which can cause a narrowing of the airways or may entrap or block blood vessels. Signs and symptoms include:[2][3][4][5]

Cough
Shortness of breath
Recurrent lung infection
Hemoptysis
Pleuritic chest pain

Occasionally people with fibrosing mediastinitis present with fever and weight loss.[2]

Fibrosing mediastinits can cause serious health complications, particularly in people who experience recurrent infection, hemoptysis, or cor pulmonale. People with fibrosing mediastinitis involving the space below the trachea or involving both sides of the mediastinum may be at a higher risk for serious complications than are people with more localized disease.[2]

Last updated: 4/23/2010

What causes fibrosing mediastinitis?

In some cases the cause of fibrosing mediastinitis cannot be determined (are “idiopathic”). Idiopathic disease has been estimated to account for roughly 10% to 20% of cases.[5] In the United States the majority of cases of fibrosing mediastinitis have been linked to Histoplasma capsulatum (H. capsulatum) infection.  

H. capsulatum
is a fungus that is found throughout the world, especially in poultry house litter, caves, areas harboring bats, and in bird roosts.[2] Histoplasma is acquired by breathing in spores from contaminated soil.[1][3][6] In the United States H. capsulatum is found along the Ohio and Mississippi River valleys, mostly in the central and southeastern states.[3] Ninety percent of infections with H. capsulatum cause no symptoms or result in a mild flu-like illness. When present, signs and symptoms of infection tend to develop 3 to 17 days following exposure.  Fibrosing mediastinitis appears to be a late and rare complication of this infection.[3]

Other cases of fibrosing mediastinitis are associated with tuberculosis, autoimmune disease, radiation therapy, and drugs (e.g., methysergide).[4]
Last updated: 4/23/2010

Is H. capsulatum related fibrosing mediastinitis genetic?

Why a small fraction of people exposed to H. capsulatum go on to develop fibrosing mediastinitis while other’s do not is not well understood. It is likely that H. capsulatum related fibrosing mediastinitis is caused by the interaction of genetic, immunologic, and environmental factors.

One study (Peebles RS et al., 2000) did find that people with H. capsulatum related fibrosing mediastinitis were approximately 3 times as likely as those without this condition to carry a certain genetic allele (or form of a gene) called  HLA-A2.[6] “HLA” stands for human leukocyte antigen. Human leukocyte antigens are an important part of our immune system and play a role in resistance and predisposition to disease. The finding of the association of H. capsulatum related fibrosing mediastinitis with HLA-A2 is noteworthy, in that it suggest that an abnormal immune response is important for the development of the disease. However, it is not uncommon for immune system diseases to be found in association with certain HLA alleles. Often times the basis of these associations are unknown, and much evidence suggests that the HLA genes are not solely responsible for specific diseases but instead may simply contribute along with other genetic or environmental factors to disease predisposition.[7]

Last updated: 4/23/2010

Can HLA-A2 typing be used to identify people at an increased risk for fibrosing mediastinitis?

No. The finding of the association of fibrosing mediastinitis with HLA-A2 does not provide much assistance in identifying individuals at an increased risk for fibrosing mediastinitis. The HLA-A2 allele is fairly common in the general population, as is exposure to H. capsulatum.[6] Eighty percent of people living in areas where H. capsulatum is common, test positive on histoplasmosis skin tests.[8] Also the vast majority of people with HLA-A2 never develop fibrosing mediastinitis.[6]
Last updated: 4/23/2010

Do people with H. capsulatum related fibrosing mediastinitis tend to have affected family members?

We did not find statistics in the literature regarding the number of people with fibrosing mediastinitis who have an affected family member. Case reports in the medical literature describing multiple affected members in the same family are very rare.[9]
Last updated: 4/23/2010

Does idiopathic fibrosing mediastinitis tend to run in families?

We are not aware of any genetic risk factors related to the idiopathic form of disease.
Last updated: 4/23/2010

Once a person has been infected with H. capsulatum can they be reinfected?

Yes. Reinfection can occur with sufficient exposure, particularly in individuals with weakened immune systems.[3]

Further information on H. capsulatum can be found on the Centers of Disease Control and Prevention Web site at the following link:
http://wwwnc.ced.gov/travel/yellowbook/2010/chapter-5/histoplasmosis.aspx
Last updated: 4/23/2010

Can histoplasmosis be transmitted from person to person?

Histoplasmosis is not transmitted directly from person to person. However, a person may be able to expose others to H. capsulatum spores if they are wearing contaminated shoes or clothing.[3]

The Centers for Disease Control and Prevention suggest taking the following measures to prevent histoplasmosis infection:

  • Persons at increased risk for severe disease (e.g., young children, elderly, and people with weakened immune system) should be advised to avoid high-risk areas, such as bat-inhabited caves.
  • If exposure cannot be avoided, persons should be advised to decrease dust generation in infested areas by watering the areas before engaging in dust-generating activities and to wear masks and special protective equipment.
  • After engaging in high-risk activities, hosing off footwear and placing clothing in airtight plastic bags to be laundered could also decrease the potential for exposure. Further details about protective equipment can be obtained from www.cdc.gov/niosh/docs/2005-109/.
  • Transportation of soil, bird droppings, and other potential spore bearing materials should be avoided.
Last updated: 4/23/2010

References
  • Histioplasmosis. MedlinePlus. 2008; http://www.nlm.nih.gov/medlineplus/ency/article/001082.htm. Accessed 4/22/2010.
  • Rossi S, McAdams H, Rosado-de-Christenson M, Franks T, Galvin J. Fibrosing Mediastinitis. Radiographics. 2001;
  • Chiller T. Chapter 5: Other infectious diseases related to travel. Centers for Disease Control and Prevention. 2009; http://wwwnc.ced.gov/travel/yellowbook/2010/chapter-5/histoplasmosis.aspx. Accessed 4/22/2010.
  • MacDonald S, Padley S. The mediastinum, including the pericardium. In: Adam A, Dixon AK. Grainger & Allison’s Diagnostic Radiology, 5th ed. Philadelphia, PA: Churchill Livingston; 2008;
  • Worrell JA, Donnelly EF, Martin JB, Bastarache JA, Loyd JE. Computed tomography and the idiopathic form of proliferative fibrosing mediastinits. J Thorac Imaging. 2007;
  • Peebles RS, Carpenter CT, Dupont WD, Loyd JE. Medistinal fibrosis is associated with human leukocyte antigen-A2*. CHEST. 2000;
  • Thompsen & Thompson. Genetic in Medicine 6th ed. Philadelphia, PA: 281-283; 2004;
  • Histoplasmosis. Centers for Disease Control and Prevention. 2008; http://www.cdc.gov/nczved/divisions/dfbmd/diseases/histoplasmosis. Accessed 4/23/2010.
  • Fibrosclerosis, multifocal. Online Mendelian Inheritance in Man. 1999; http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=228800. Accessed 4/23/2010.
  • Devaraj A, Griffin N, Nicholson AG, Padley SPG. Computed tomography findings in fibrosing mediastinitis. Clinical Radiology. 2007;
Other Names for this Disease
  • Idiopathic mediastinal fibrosis
  • Mediastinal fibrosis
  • Sclerosing mediastinitis
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.