Restrictive Lung Diseases Restrictive Lung Diseases 1 2

Restrictive Lung Diseases

Restrictive Lung Diseases 1. 2. 3. 4. 5. 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, 25 dihydroxyvitamin D by sarcoid macrophage).

Morphology: 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: CD 4/CD 8 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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