acute fibrinous organizing pneumonia

Acute fibrinous and organizing pneumonia (AFOP) is the most recently recognized of the lesions that are associated with ARDS. It is characterized by the presence of masses or balls of fibrin within alveoli accompanied by organizaton of varying degree.

AFOP may resemble organizing pneumonia. However, intra-alveolar fibrin masses are not a feature of organizing pneumonia..

Lesions

 intra-alveolar fibrin (alveolar fibrinous exudates)
 organizing pneumonia (pulmonary organization)
 type 2 pneumocyte hyperplasia
 edema
 acute inflammation and chronic inflammation (inflammatory infiltrate)
 pulmonary interstitial widening

Associations

 collagen vascular disease

• inflammatory myopathy
• juvenile dermatomyositis (15689928)

 amiodarone
 Haemophilus influenza
 Acinetobacter lymphomaairspray
 severe acute respiratory syndrome (SARS) (15272286)
 construction work
 coal mining
 zoological work

Differential diagnosis

 organizing pneumonia

Links

 Acute fibrinous & organizing pneumonia (AFOP) at the Yale Rosen Collection

References

 Beasley MB, Franks TJ, Galvin JR, Gochuico B, Travis WD. Acute fibrinous and organizing pneumonia: a histological pattern of lung injury and possible variant of diffuse alveolar damage. Arch Pathol Lab Med. 2002 Sep;126(9):1064-70. PMID: 12204055