Restrictive Lung Diseases
Restrictive Lung Diseases
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Adult respiratory distress syndrome
Sarcoidosis
Asbestosis
Neonatal respiratory distress syndrome
Idiopathic Pulmonary fibrosis
Acute respiratory distress syndrome
1. Def: Diffuse damage primarily to type 1
pneumocytes + capillary: followed by injury of
type 2 cells and endothelium.
2. Cause: gm - ve Sepsis, trauma, lung infection
etc.
3. Pathogenesis:
1. Diffuse alveolar damage: DAD
2. In E coli infection this DAD is mediated by
free radicals from Neutrophils.
Respiratory membrane
Alveolar sac
Hyaline membrane
ARDS
Morphology:
– Gross: lung is diffusely firm, airless, and
rubbery.
– Micro: Hyaline membrane
Clinical:
– acute dyspnea, cyanosis, hypoxemia.
– X ray: white out : bilateral lung opacity
– Unresponsive to 100% oxygen treatment.
– Mortality is between 30-40%.
Intra alveolar hyaline membrane: fibrin and cell
debris → reduced oxygen diffusion.
Whiteout
End
Neonatal respiratory distress syndrome
Reduced surfactant due to defective
pneumocytes 2.
Clinical similar to ARDS
Sarcoidosis
Sarcoidosis
Definition: disease with non caseating
granulomas, can involve any organ.
Most common presentation.
– Bilateral hilar lymphadenopathy and /or lung
involvement.
Hyper-calcemia is present ( due to high 1,25dihydroxyvitamin D by sarcoid macrophage).
Morphology: Micro
Microscopy :
– Non caseating epithelioid cell granulomas in
all effected organs with giant cells.
– Hilar node: These lympnnode may undergo
calcification: egg shell calcification.
Giant cells contain these structures
Schuamann body
Concentric calcification
Asteroid bodies
Clinical Course of Sarcoidosis
Asymptomatic, discovered incidentally (many
cases).
Dry cough/ night sweat/ fever.
Eye involvement: Mikulicz syndrome: corneal
opacity, blindness.
Skin involvement: erythema nodosum (painful
erythematous plaques or rash).
Sarcoidosis : diagnosis
Final diagnosis is by lung LN biopsy or
biopsy of the skin or eye lesion.
Helpful: CD4/CD8 ratio >2.5 ( in
bronchoalveolar lavage lymphocytes) –
PPD negative.
End
Asbestosis
Cause: Asbestos fibers
Morphology of lung:
Early: diffuse interstitial fibrosis in lower lobe and
fibrous pleural plaque [parietal pleura] .
Late stage: honeycomb lung.
Complications: bronchogenic carcinoma,
mesothelioma.
Asbestos fibers : morphology
Asbestos body or Ferruginous body which
is positive with Prussian blue.
– Amphibole (thin and straight) and
serpentine (curly. Flexible, common ).
– Present in extracellular tissue in lung
interstitium (initial ingested by macrophage
that eventually dies off).
Asbestosis : morphology
Ferruginous body which is positive with Prussian blue.
They arise when macrophages attempt to phagocytose
asbestos fibers.
Late change: “Honeycomb" lung.
It is the end stage of all restrictive lung diseases
Pulmonary hypertension
Pulmonary hypertension → right ventricular
hypertrophy.
Primary
Secondary
More common
1. Multiple pulmonary emboli
2. Increased blood flow ( left-to-right
shunt).
3. COPD and restrictive lung disease :
these cause hypoxia induced
vasoconstriction.
Primary Pulmonary Hypertension
Etiology: unknown
Morphology: plexiform pulmonary angiopathy
and medial hypertrophy.
Secondary Pulmonary Hypertension
Morphology:
– Medial hypertrophy
– Or presence fibrotic organized emboli in
vessels with narrow lumen.
Complications of Pulmonary Hypertension
Right ventricular hypertrophy → Right
heart failure or cor pulmonale
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