Fibrosis

Fibrosis
Classification and external resources
Micrograph of a heart showing fibrosis (yellow - left of image) and amyloid deposition (brown - right of image). Movat's stain.
MeSH	D005355

Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue. Scarring is confluent fibrosis that obliterates the architecture of the underlying organ or tissue.

The term is also sometimes used to describe a normal healing process, but this usage is less common.

Examples of fibrosis

Micrograph showing cirrhosis of the liver. The tissue in this example is stained with a trichrome stain, in which fibrosis is colored blue. The red areas are the nodular liver tissue

• Pulmonary fibrosis (lungs)
  • Idiopathic pulmonary fibrosis (where the cause is unknown)
  • Cystic fibrosis
• Cirrhosis (liver)
• Endomyocardial fibrosis (heart)
• Mediastinal fibrosis (soft tissue of the mediastinum)
• Myelofibrosis (bone marrow)
• Retroperitoneal fibrosis (soft tissue of the retroperitoneum)
• Progressive massive fibrosis (lungs); a complication of coal workers' pneumoconiosis
• Nephrogenic systemic fibrosis (skin)
• Crohn's Disease (intestine)
• Keloid (skin)
• Old myocardial infarction (heart)
• Scleroderma/systemic sclerosis (skin, lungs)
• Arthrofibrosis (knee, shoulder, other joints)
• Some forms of adhesive capsulitis (shoulder)

Types

Type	Most common location(s)	Circumscription	Cellularity	Vascularity and nature of vessels	Appearance of collagen	Elastic fibers	Picture
Nuchal fibroma	Nuchal region	No	Very low	Very low	Bundles of fibers	Scant
Collagenous fibroma	Shoulder girdle, extremities	Yes, by macroscopic appearance, but microscopically infiltrative	Increased but generally low	Low	Scant or absent	Amorphous
Fibroma of tendon sheath	Distal extremities, especially the hand	Yes	Low to high	Moderate to high, with some slitlike vessels	Amorphous	Absent
Scar	Variable	Variable	Low to high	Variable	Amorphous	Scant to absent
Elastofibroma	Subscapular chest wall	No	Low to moderate	Low	Amorphous	Abundant and abnormal
Desmoid-type fibromatosis	Abdominal wall, shoulder girdle	Yes, by macroscopic appearance, but microscopically infiltrative	Moderate	Moderate, mildly dilated	Amorphous	Absent
Keloid	Upper part of back, deltoid, presternal, ear lobes	No	Some fibroblasts	Low	Amorphous thick eosinophilic bundles	Scant or Absent

External links

• "Fibrosis" at Dorland's Medical Dictionary

• International Scar Meeting in Tokyo 2010 International Scar Meeting

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