|
|
Line 181: |
Line 181: |
| 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= |