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{{Cryptogenic organizing pneumonia}}
{{Cryptogenic organizing pneumonia}}


{{CMG}} {{AE}} {{SSK}}
{{CMG}} {{AE}} {{MKK}} {{SSK}}


==Overview==
==Overview==
 
[[Cryptogenic organizing pneumonia]] is an idiopathic diffuse [[interstitial lung disease]] that affects the distal [[bronchioles]], respiratory [[bronchioles]], [[alveolar ducts]], and [[alveolar]] walls. The injury occurs within the [[alveolar]] wall. There is proliferation of [[granulation tissue]] which involves [[alveolar ducts]] and [[alveoli]]. There are 4 phases lead to the formation of mature fibrotic bud.
==Pathophysiology==
*The organizing pneumonia pathogenesis model is very similar to the that of cutaneous wound healing.
*Following an insult, a recovery phase characterized by the organisation of inflammatory exudates with resulting intra-alveolar fibrosis ensues.  
*Although the intra-alveolar fibrosis resembles that present in usual interstitial pneumonia (UIP), it is however not associated with irreversible  fibrosis. In contrast, cryptogenic organizing pneumonia is characterized by it's favorable response to corticosteroid therapy.<ref name="pmid16880372">{{cite journal| author=Cordier JF| title=Cryptogenic organising pneumonia. | journal=Eur Respir J | year= 2006 | volume= 28 | issue= 2 | pages= 422-46 | pmid=16880372 | doi=10.1183/09031936.06.00013505 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16880372  }} </ref>
 


==Pathophysiology==
==Pathophysiology==


===Pathogenesis===
===Pathogenesis===
*It is understood that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].
[[Cryptogenic organizing pneumonia]] is caused by excessive proliferation of [[granulation tissue]] which involves [[alveolar ducts]] and [[alveoli]]. [[Granulation tissue]] may extend from one [[alveolus]] to the adjacent one leading to the formation of mature fibrotic bud which gives characteristic "butterfly" pattern.
*[Pathogen name] is usually transmitted via the [transmission route] route to the human host.
*Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.
*[Disease or malignancy name] arises from [cell name's, which are [cell type] cells that are normally involved in [function of cells].
*The progression to [disease name] usually involves the [molecular pathway].
*The pathophysiology of [disease/malignancy] depends on the histological subtype.
 
 
1) '''Injury phase''' - The early phase of cryptogenic organizing pneumonia.
*It is characterized by the deposition of plasma proteins in the alveolar lumen.
*Mechanism of early phase is an imbalance between coagulation and fibrinolytic cascade and activation of coagulation process which leads to fibrin deposition


2) '''Proliferating phase''' - The second stage of the cryptogenic organizing pneumonia in which there is a  formation of fibroinflammatory buds.
Various phases involved in the pathogenesis of [[cryptogenic organizing pneumonia]] are:<ref name="pmid11790668">{{cite journal |vauthors= |title=American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001 |journal=Am. J. Respir. Crit. Care Med. |volume=165 |issue=2 |pages=277–304 |date=January 2002 |pmid=11790668 |doi=10.1164/ajrccm.165.2.ats01 |url=}}</ref>
* Macrophages and inflammatory cells helps in fragmentation of fibrin.
* Activated fibroblasts differentiate into myofibroblasts  which is migrating  through gaps of the basal lamina.
* Inflammatory cells and fibrin are progressively replaced by aggregated fibroblasts/myofibroblasts intermixed with a loose connective matrix tissue rich in collagen (especially collagen I), fibronectin, procollagen type III and proteoglycans.
* Alveolar epithelial cells proliferate, restoring the continuity of the alveolar-capillary membrane and the integrity of the alveolar unit.
3) '''Mature phase''' The third stage () is characterized by “mature” fibrotic buds clearly delineated inside the alveolar space. Inflammatory cells and fibrin deposits are no longer found in alveolar buds, which are mostly constituted by typical myofibroblasts (with cytoplasmic filaments orientated toward the cell axis), organized in concentric rings alternating with layers of collagen bundles. At this stage, the connective network consists of thin collagen-I fibers together with thinner fibrils of collagen and procollagen type III, and fibronectin.


In a fourth stage (resolution phase), this process resolves without significant sequelae, similar to reversible wound healing in the skin. The relative preservation of the alveolar basal laminae is considered to be required for the reversibility of the lesions.
1) '''Injury phase''' - The early phase of [[cryptogenic organizing pneumonia]].
*It is characterized by the deposition of [[plasma proteins]] in the [[alveolar]] lumen.
*Mechanism of early phase is an imbalance between [[coagulation]] and [[fibrinolytic]] cascade and activation of [[coagulation]] process which leads to [[fibrin]] deposition.<ref name="pmid16880372">{{cite journal |vauthors=Cordier JF |title=Cryptogenic organising pneumonia |journal=Eur. Respir. J. |volume=28 |issue=2 |pages=422–46 |date=August 2006 |pmid=16880372 |doi=10.1183/09031936.06.00013505 |url=}}</ref>


==Genetics==
2) '''Proliferating phase''' - The second stage of the [[cryptogenic organizing pneumonia]] in which there is a  formation of fibro-[[inflammatory]] buds.
*[Disease name] is transmitted in [mode of genetic transmission] pattern.
* [[Macrophages]] and [[inflammatory cells]] help in fragmentation of [[fibrin]].
*Genes involved in the pathogenesis of [disease name] include [gene1], [gene2], and [gene3].
* Activated [[fibroblasts]] differentiate into [[myofibroblasts]] which are migrating through gaps of the [[basal lamina]].
*The development of [disease name] is the result of multiple genetic mutations.
* [[Inflammatory cells]] and [[fibrin]] are progressively replaced by aggregated [[fibroblasts]]/[[myofibroblasts]] intermixed with a [[Loose connective tissue|loose connective]] matrix tissue rich in [[collagen]] (especially collagen I), [[fibronectin]], [[procollagen]] type III and [[proteoglycans]].
* [[Alveolar]] [[epithelial cells]] proliferate, restoring the continuity of the [[Alveolar-capillary barrier|alveolar-capillary]] membrane and the integrity of the [[alveolar]] unit.
3) '''Mature phase''' - The third stage is characterized by the formation of mature fibrotic buds which gives characteristic "butterfly" pattern.
*In [[alveolar]] buds, there are [[myofibroblasts]], organized in [[concentric]] rings alternating with layers of [[collagen]] bundles.
4)'''Resolution phase''' - The fourth stage, this stage usually resolves if there is the preservation of [[alveolar]] basal laminae.


==Associated Conditions==
==Associated Conditions==
[[Cryptogenic organizing pneumonia]] is associated with the following conditions:<ref name="urlOrganising pneumonia | Thorax">{{cite web |url=http://thorax.bmj.com/content/55/4/318#ref-3 |title=Organising pneumonia &#124; Thorax |format= |work= |accessdate=}}</ref><ref name="pmid7890282">{{cite journal |vauthors=Kwon KY, Myers JL, Swensen SJ, Colby TV |title=Middle lobe syndrome: a clinicopathological study of 21 patients |journal=Hum. Pathol. |volume=26 |issue=3 |pages=302–7 |date=March 1995 |pmid=7890282 |doi= |url=}}</ref>
*Infectious [[pneumonia]]
*[[Lung abscess]]
*[[Empyema]]
*[[Lung cancer]]
*Chronic [[pulmonary fibrosis]]
*[[Aspiration pneumonia]]
*[[Acute respiratory distress syndrome|Adult respiratory distress syndrome]]
*[[Pulmonary infarction]]
*Middle lobe syndrome


==Gross Pathology==
==Gross Pathology==
*On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
On gross pathology of [[cryptogenic organizing pneumonia]], following features are seen:
*There is the firm area with preservation of [[lung]] pattern which extends to thickened [[Pleurae|pleura]].<ref name="urlOrganising pneumonia | Thorax">{{cite web |url=http://thorax.bmj.com/content/55/4/318 |title=Organising pneumonia &#124; Thorax |format= |work= |accessdate=}}</ref>


==Microscopic Pathology==
==Microscopic Pathology==
On microscopic histopathological analysis:<ref name="urlCryptogenic organising pneumonia | Radiology Reference Article | Radiopaedia.org">{{cite web |url=https://radiopaedia.org/articles/cryptogenic-organising-pneumonia-1 |title=Cryptogenic organising pneumonia &#124; Radiology Reference Article &#124; Radiopaedia.org |format= |work= |accessdate=}}</ref>
On microscopic histopathological analysis:<ref name="urlCryptogenic organising pneumonia | Radiology Reference Article | Radiopaedia.org">{{cite web |url=https://radiopaedia.org/articles/cryptogenic-organising-pneumonia-1 |title=Cryptogenic organising pneumonia &#124; Radiology Reference Article &#124; Radiopaedia.org |format= |work= |accessdate=}}</ref><ref name="pmid29404167">{{cite journal |vauthors=Akyıl FT, Ağca M, Mısırlıoğlu A, Arsev AA, Akyıl M, Sevim T |title=Organizing Pneumonia as a Histopathological Term |journal=Turk Thorac J |volume=18 |issue=3 |pages=82–87 |date=July 2017 |pmid=29404167 |pmc=5783087 |doi=10.5152/TurkThoracJ.2017.16047 |url=}}</ref>
*It is characterized by chronic mild interstitial inflammation without fibrosis.
*It is characterized by chronic mild interstitial [[inflammation]] without [[fibrosis]].
*There is the formation of buds of granulation tissue which is made of fibrous tissue (Masson bodies),  mononuclear cells and foamy macrophages, in the distal airspaces which cause secondary bronchiolar occlusion due to the presence of the inflammatory process.
*There is the formation of buds of [[granulation tissue]] which is made of [[fibrous tissue]] (Masson bodies),  [[mononuclear cells]] and foamy [[macrophages]], in the distal airspaces which cause [[secondary]] bronchiolar [[occlusion]] due to the presence of the [[inflammatory process]].
[[File:Masson body - high mag.jpg|200px|thumb|centre| source:By Nephron<ref>https://commons.wikimedia.org/w/index.php?curid=17325428</ref>]]


==References==
==References==

Latest revision as of 14:16, 28 March 2018

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Manpreet Kaur, MD [2] Serge Korjian M.D.

Overview

Cryptogenic organizing pneumonia is an idiopathic diffuse interstitial lung disease that affects the distal bronchioles, respiratory bronchioles, alveolar ducts, and alveolar walls. The injury occurs within the alveolar wall. There is proliferation of granulation tissue which involves alveolar ducts and alveoli. There are 4 phases lead to the formation of mature fibrotic bud.

Pathophysiology

Pathogenesis

Cryptogenic organizing pneumonia is caused by excessive proliferation of granulation tissue which involves alveolar ducts and alveoli. Granulation tissue may extend from one alveolus to the adjacent one leading to the formation of mature fibrotic bud which gives characteristic "butterfly" pattern.

Various phases involved in the pathogenesis of cryptogenic organizing pneumonia are:[1]

1) Injury phase - The early phase of cryptogenic organizing pneumonia.

2) Proliferating phase - The second stage of the cryptogenic organizing pneumonia in which there is a formation of fibro-inflammatory buds.

3) Mature phase - The third stage is characterized by the formation of mature fibrotic buds which gives characteristic "butterfly" pattern.

4)Resolution phase - The fourth stage, this stage usually resolves if there is the preservation of alveolar basal laminae.

Associated Conditions

Cryptogenic organizing pneumonia is associated with the following conditions:[3][4]

Gross Pathology

On gross pathology of cryptogenic organizing pneumonia, following features are seen:

  • There is the firm area with preservation of lung pattern which extends to thickened pleura.[3]

Microscopic Pathology

On microscopic histopathological analysis:[5][6]

source:By Nephron[7]

References

  1. "American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001". Am. J. Respir. Crit. Care Med. 165 (2): 277–304. January 2002. doi:10.1164/ajrccm.165.2.ats01. PMID 11790668.
  2. Cordier JF (August 2006). "Cryptogenic organising pneumonia". Eur. Respir. J. 28 (2): 422–46. doi:10.1183/09031936.06.00013505. PMID 16880372.
  3. 3.0 3.1 "Organising pneumonia | Thorax".
  4. Kwon KY, Myers JL, Swensen SJ, Colby TV (March 1995). "Middle lobe syndrome: a clinicopathological study of 21 patients". Hum. Pathol. 26 (3): 302–7. PMID 7890282.
  5. "Cryptogenic organising pneumonia | Radiology Reference Article | Radiopaedia.org".
  6. Akyıl FT, Ağca M, Mısırlıoğlu A, Arsev AA, Akyıl M, Sevim T (July 2017). "Organizing Pneumonia as a Histopathological Term". Turk Thorac J. 18 (3): 82–87. doi:10.5152/TurkThoracJ.2017.16047. PMC 5783087. PMID 29404167.
  7. https://commons.wikimedia.org/w/index.php?curid=17325428

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