Lung Pathology

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Strength is Life Weakness is
Death Swami Vivekananda
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Lung - Pathology
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• Diffuse Interstitial (Restrictive) Diseases
• Heterogeneous group
• 15 of noninfectious pulmonary diseases
• Unknown cause and pathogenesis
• Lead to Diffuse and usually chronic involvement
  of the lung
• End-stage lung or Honeycomb lung

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Lung Pathology Diffuse Interstitial
(Restrictive) Diseases
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• Collagen Vascular Diseases (SLE, RA, Systemic
  sclerosis (scleroderma)
• Pulmonary involvement indicates poor prognosis
• SLE - patchy, transient parenchymal infiltrates
• Systemic sclerosis NSIP (Nonspecific
  interstitial pneumonia )
• Rheumatoid arthritis (RA)
• Pulmonary
• diffuse interstitial pneumonitis and fibrosis
• intrapulmonary rheumatoid nodules
• pulmonary hypertension
• Pleural
• chronic pleuritis, Effusions, pleural nodules

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Lung Pathology Diffuse Interstitial
(Restrictive) Diseases
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• Pneumoconiosis
• Lung reaction to inhalation of mineral dusts in
  the workplace
• organic inorganic particulates
• chemical fumes and vapors
• General Pathogenesis
• most dangerous particles of size range from 1 to
  5 µm
• Coal workers pneumoconiosis (CWP)
• Disease spectrum of coal dust-induced disease
• Asymptomatic Anthracosis
• Simple coal workers' pneumoconiosis (CWP)
• Complicated CWP, or progressive massive fibrosis
  (PMF)
• Pathogenesis incompletely understood
• Affect mainly upper lobes
• Cause In most cases -carbon dust
• Clinical Course
• benign disease
• But in PMF patients
• progressive
• Develop pulmonary dysfunction, pulmonary HTN
  Cor Pulmonale

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MorphologyCoal workers pneumoconiosis (CWP)
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COAL WORKERS PNEUMOCONIOSIS (CWP)
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• Silicosis
• MC chronic occupational disease in the world
• caused by inhalation of crystalline silicon
  dioxide (silica).
• Acute silicosis -accumulation of a
  lipoproteinaceous material within alveoli
• Chronic silicosis - slowly progressing, nodular,
  Fibrosing pneumoconiosis
• Pathogenesis
• crystalline forms -more fibrogenic (quartz
  worst)
• silica particles ?lung macrophages ingest them ?
  activation and release of mediators ? IL-1, TNF,
  oxygen-derived free radicals
• Anti-TNF monoclonal antibodies can block lung
  collagen accumulation in mice
• Morphology.
• Early stages tiny nodules in the upper zones
• disease progresses nodules coalesce into hard,
  collagenous scars ?central softening and
  cavitation (due to superimposed tuberculosis or
  to ischemia)
• X-ray egg shell calcification in the lymph
  nodes
• Advanced stage - PMF
• Histology
• Nodular lesions -concentric layers of hyalinized
  collagen surrounded by a dense capsule
• Birefringent silica particles in polarized
  microscopy

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Silicosis
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• Asbestos-Related Diseases
• Localized fibrous plaques or diffuse pleural
  fibrosis
• Pleural effusions
• Parenchymal interstitial fibrosis (asbestosis)
• Lung carcinoma
• Mesotheliomas
• Laryngeal and extra pulmonary neoplasms, (colon
  carcinomas)
• Pathogenesis.
• Two forms of asbestos
• serpentine (curly and flexible fibers)
• most of the asbestos used in industry
• amphibole (straight, stiff, and brittle fibers).
  
• induction of malignant pleural tumors
  (mesotheliomas)
• Morphology.
• Asbestosis diffuse pulmonary interstitial
  fibrosis,
• Asbestos bodies or Ferruginous bodies
• golden brown, fusiform or beaded rods
• macrophages engulf of asbestos fibers coated with
  an iron-containing proteinaceous material

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• Asbestos Neoplasms
• act as a tumor initiator tumor promoter.
• Oncogenic effects mediated by
• 1. reactive free radicals generated by asbestos
  fibers (localize in the distal lung close to
  the mesothelial layers)
• 2. chemicals adsorbed onto the asbestos fibers
• Example- tobacco smoke
• Lung involvement
• Begins as fibrosis around respiratory bronchioles
  and alveolar ducts
• Extends to adjacent alveolar sacs and alveoli.
• Eventually - honeycombed.
• In contrast to CWP and silicosis,
• Begins in the lower lobes and subpleurally.
• middle and upper lobes affected later
• Pleural plaques
• MC manifestation of asbestos exposure
• MC site- anterior and posterolateral aspects of
  parietal pleura
• domes of the diaphragm.
• not contain asbestos bodies
• always history of evidence of asbestos exposure.

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Lung Pleural involvement
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Forms of asbestos
Both are fibrogenic Both associated with ?all
asbestos-related disease except Mesothelioma
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Asbestos-Related cancers
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• Asbestos-Related Diseases
• Complications
• Scarring trap pulmonary arteries and arterioles?
  pulmonary HTN Cor Pulmonale.
• Clinical Course.
• manifestations appear gt 20 years of exposure
• Clinical findings - similar to other causes of
  diffuse interstitial lung disease
• Dyspnea - first manifestation accompanied by a
  cough
• associated with production of sputum.
• static or progress to respiratory failure, Cor
  Pulmonale, and death
• X-ray
• irregular linear densities- both lower lobes.
• Later - honeycomb pattern
• Prognosis
• If lung or pleural cancer - grim prognosis