Difference between revisions of "Medical lung diseases"

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6,186 bytes removed ,  14:54, 4 November 2011
→‎Disease with fibrosis: move to diffuse lung diseases
(→‎Idiopathic interstitial pneumonia: split-out into separate article)
(→‎Disease with fibrosis: move to diffuse lung diseases)
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There are many of 'em.
There are many of 'em.


==Diffuse alveolar damage==
*[[Diffuse alveolar damage]].
===General===
*[[Usual interstitial pneumonia]].
*Abbreviated ''DAD''.
*[[Asbestosis]].
 
*[[Hypersensitivity pneumonitis]].
DAD is the histologic correlate of:
*Adult respiratory distress syndrome (ARDS).
*Acute interstitial pneumonia (AIP).
*Transfusion related acute lung injury (TRALI).
 
===Microscopic===
Features:<ref name=Ref_Klatt103>{{Ref Klatt|103}}</ref>
*Early:
**Hyaline membrane: debris (pink crap) lines the alveolar spaces.
*Intermediate:
**Macrophage proliferation.
*Late:
**Interstitial inflammation.
**Fibrosis.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Hyaline_membranes_-_intermed_mag.jpg DAD - intermed. mag. (WC)].
*[http://en.wikipedia.org/wiki/File:Hyaline_membranes_-_very_high_mag.jpg DAD - very high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:ARDS.jpg DAD (WC)].
 
==Usual interstitial pneumonia==
===General===
*It is sometimes used incorrectly as a synoym for ''idiopathic pulmonary fibrosis''.
*Cannot be diagnosed via bronchoscopic or transbronchial biopsy.<ref name=Ref_PPP186>{{Ref PPP|186}}</ref>
 
====Epidemiology====
*Disease of the old - rare in under 50 years old.<ref>AC UBC S.102.</ref>
*Dismal prognosis - mean survival after diagnosis ~ 2.8 years.<ref name=pmid9445300/>
 
====Differential diagnosis====
UIP is seen in:<ref name=leslie>{{cite book |author=Wick, Mark R.; Leslie, Kevin |title=Practical pulmonary pathology: a diagnostic approach |publisher=Churchill Livingstone |location=Edinburgh |year=2005 |pages= |isbn=0-443-06631-0 |oclc= 156861539|doi= |accessdate=}}</ref>
*Idiopathic pulmonary fibrosis.
*Asbestosis - one ought to see ''ferruginous bodies''.
*Chronic hypersensitivity pneumonitis (extrinsic allergic alveolitis).
*Collagen vascular disease - includes [[systemic lupus erythematousus]], [[rheumatoid arthritis]], [[scleroderma]].<ref>{{Ref PCPBoD8|374}}</ref>
*Chronic drug toxicity.<ref>{{cite journal |author=Rossi SE, Erasmus JJ, McAdams HP, Sporn TA, Goodman PC |title=Pulmonary drug toxicity: radiologic and pathologic manifestations |journal=Radiographics : a review publication of the Radiological Society of North America, Inc |volume=20 |issue=5 |pages=1245-59 |year=2000 |pmid=10992015 |doi=}}</ref>
 
===Radiologic===
*Honeycombing - ''multiple'' defects that obliterate the normal lung architecture - multiple spherical voids in the lung parenchyma; radiologically these are seen as lucencies.<ref>[http://www.medcyclopaedia.com/library/topics/volume_v_1/h/honeycombing.aspx http://www.medcyclopaedia.com/library/topics/volume_v_1/h/honeycombing.aspx]</ref>
**Usually subplural, i.e. peripheral lung.
**Classically lower lobe predominant.
**Associated with interstitial thickening. (???)
 
Note:
*Cysts - have thin walls (think of emphysema, lymphangioleiomyomatosis et cetera).
**Cysts may be isolated/not close to a neighbour.
**Medcyclopaedia defines it as: thin-walled, well-demarcated and >1 cm.<ref>[http://www.medcyclopaedia.com/library/topics/volume_v_1/l/lung_cyst.aspx http://www.medcyclopaedia.com/library/topics/volume_v_1/l/lung_cyst.aspx]</ref>
 
===Microscopic===
Features:<ref name=Ref_PPP186-9>{{Ref PPP|186-9}}</ref>
*Fibroblast foci:
**"Crescent-shaped bulge" of fibroblasts -- a rounded projection of spindle cells into the airspace.
**Location: in the areas of transisition between active inflammation and old inflammation.<ref>[http://www.epler.com/IPFWhat%27sIPFDiseaseInformation2.htm http://www.epler.com/IPFWhat%27sIPFDiseaseInformation2.htm]</ref>
**Note: Technically, ''fibroblast foci'' are composed of myofibroblasts.<ref name=Ref_PPP189>{{Ref PPP|189}}</ref>
*Interstitial inflammation,
*Microscopic honeycombing,
**Typically peripheral - cysts lined by ciliated epithelium.
*Spatial heterogeneity - patchy lesional distribution (areas of abnormal and normal lung may appear beside one another).
*Temporal heterogeneity - lesions of differing age side-by-side.<ref>H. 8 July, 2009.</ref>
 
Notes:
*Disease worse distant from large airways: lower lung field predominance, typically worse at periphery of lobule and lung.<ref>A. Churg. UBC S.103.</ref>
*Heterogeneity of inflammation: airspace macrophages & inflammation minimal in honeycombed foci.
 
==Asbestosis==
===General===
*Important to diagnose... asbestosis = compensation.
 
===Microscopic===
*Histologic appearance as for UIP -- plus ''ferruginous bodies''.
**Segmented twirling batton with long slender fibre within.
 
Image(s):
*[http://commons.wikimedia.org/wiki/File:Ferruginous_body.jpg Ferruginous bodies (WC)].
*[http://commons.wikimedia.org/wiki/File:Asbestosis_high_mag.jpg Asbestosis (WC)].
 
==Non-specific interstitial pneumonia==
*Abbreviated ''NSIP''.
*Better prognosis than UIP.
*Some radiologists and pathologists don't believe in this entity.
 
===Gross/Radiology===
*No honeycombing.
*Fibrosis usually lower lung zone.
*Patchy ground glass.
 
===Microscopic===
*Fibrosis:
**May be uniform.
**"Linear fibrosis" has a good prognosis - should be mentioned in the report.
***''Linear fibrosis'' = fibrosis that follows alveolar walls + no architectural distortion.
*+/-Lymphoid nodules - assoc. with collagen vascular disease.
 
Notes:
*Like UIP... also temporally and spatially heterogeneous.
*Inflammation in NSIP usually more prominent than in UIP.
*No honeycombing - key difference between UIP and NSIP.
 
===DDx===
*Collagen vascular disease.
*Drug reaction.
*Hypersensitivity pneumonitis (extrinic allergic alveolitis).
 
==Hypersensitivity pneumonitis==
*AKA ''extrinsic allergic alveolitis''
*Exposure to stuffs... e.g. moldy hay - ''Farmer's lung'', atypical mycobacteria - ''hot tub lung''.
*Upper lung predominant disease (???).
 
===Microscopic===
Features:
* Lesions have centrilobular prominence - '''important feature'''. <ref name=pmid16061708/>
** Allergens enter lung through airway which has a centrilobular location.
* [[Granulomata]] (not typically seen in UIP) - '''important feature'''.<ref name=pmid16061708>PMID 16061708.</ref>
* Chronic interstitial inflammation consisting primarily of lymphocytes.
* Interstitial fibrosis.
* Air space involvement (alveolitis).
 
Images:
*[http://commons.wikimedia.org/wiki/File:Hypersensitivity_pneumonitis_intermed_mag.jpg Hypersensitivity pneumonitis - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Hypersensitivity_pneumonitis_high_mag.jpg Hypersensitivity pneumonitis - high mag. (WC)].


=Lymphocytic lesions of the lung=
=Lymphocytic lesions of the lung=
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