Pleural Diseases

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Pleural Effusions - Fluid Follies

Fluid in pleural space. Differentiated by Light's Criteria.

  • Light's Criteria (Exudate if ≥1):
    • Pleural/Serum Protein > 0.5
    • Pleural/Serum LDH > 0.6
    • Pleural LDH > $\frac{2}{3}$ ULN serum LDH (>200 IU/L)
  • Transudate (Systemic: ↑Hydrostatic/↓Oncotic pressure):
    • CHF (commonest), Cirrhosis, Nephrotic Syndrome, PE.
  • Exudate (Local: ↑Pleural permeability/↓Lymphatic drainage):
    • Infection (Pneumonia, TB - commonest exudative in India), Malignancy, PE, Autoimmune.

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  • Features: Dyspnea, cough, pleuritic pain. Stony dullness, ↓breath sounds.
  • Dx: CXR (PA >200ml, Lat Decubitus >50ml), Thoracentesis.
  • Rx: Treat cause. Therapeutic tap for large effusions.

Meigs' syndrome: Benign ovarian tumor + ascites + pleural effusion (transudate). Resolves post-tumor removal.

Pneumothorax - Air Escapades

  • Definition: Air in pleural space → lung collapse.
  • Types:
    • Spontaneous:
      • Primary (PSP): No lung disease; apical bleb rupture (tall, thin young males).
      • Secondary (SSP): Underlying lung disease (COPD, TB, asthma).
    • Traumatic: Penetrating/blunt chest trauma.
    • Iatrogenic: Post-medical procedure (central line, biopsy).
  • Tension Pneumothorax: ⚠️ Emergency!
    • One-way valve → ↑ intrapleural pressure.
    • Mediastinal shift (away), ↓ venous return, cardiovascular collapse. Tracheal deviation.
  • Clinical: Acute dyspnea, pleuritic pain, ↓ breath sounds, hyperresonant percussion.
  • Diagnosis:
    • CXR: Visceral pleural line, absent lung markings. Deep sulcus sign (supine).
    • USG: No lung sliding ("barcode sign"); lung point sign (specific).
    • CT: Most sensitive; detects small pneumothorax, bullae. Chest X-ray: Left Pneumothorax with Mediastinal Shift
  • Management:
  • Pleurodesis: For recurrent/persistent cases (talc, doxycycline).

Deep Sulcus Sign: On supine CXR, a deep, lucent costophrenic angle suggests pneumothorax.

Pleuritis & Empyema - Inflammatory Invasions

  • Pleuritis: Pleural inflammation. Causes: Infection (pneumonia, TB), malignancy, autoimmune (SLE). Sx: Sharp pleuritic chest pain, fever.
  • Empyema: Pus in pleural space. Common organisms: S. aureus, S. pneumoniae, anaerobes.
    • Stages:
      • Exudative: Sterile exudate, ↑capillary permeability.
      • Fibrinopurulent: Bacterial invasion, frank pus, fibrin deposition.
      • Organizing: Fibroblast proliferation, thick pleural peel, potential trapped lung.
    • Diagnosis: Thoracentesis. Pleural fluid: pH < 7.20, glucose < 60 mg/dL, LDH > 1000 IU/L, ↑WBCs, positive Gram stain/culture.

    ⭐ Frank pus on aspiration, positive Gram stain/culture from pleural fluid, OR pleural fluid pH < 7.20 confirms empyema.

  • Treatment: Systemic antibiotics, complete pleural fluid drainage (e.g., chest tube, VATS/decortication). Complication: Fibrothorax. CT scan: Loculated empyema, thick rind, non-expandable lung

Pleural Tumors - Neoplastic Nightmares

  • Primary tumor: Malignant Mesothelioma (MM); Secondary: Metastases (more common).
  • Malignant Mesothelioma (MM)
    • Strongly linked to asbestos exposure (long latency: 20-40 years). 📌 "A"sbestos for "M"esothelioma.
    • Gross: Thick, white, gelatinous sheets encasing lung ("pleural rind"). Gross malignant mesothelioma encasing lung
    • Histology:
      • Epithelioid (most common, ~60%; better prognosis).
      • Sarcomatoid (~20%; worst prognosis).
      • Biphasic (~20%; intermediate prognosis).
    • IHC Markers: Calretinin+, WT-1+, CK5/6+, D2-40+ (positive); CEA- (negative) (vs. Adenocarcinoma).
    • Symptoms: Insidious onset chest pain, dyspnea, weight loss, recurrent effusions.

    ⭐ Psammoma bodies can be seen in epithelioid mesothelioma.

  • Metastatic Pleural Tumors
    • Most common pleural malignancy.
    • Primaries: Lung > Breast > Ovary, Lymphoma.
    • Often presents as malignant pleural effusion, leading to dyspnea.

High‑Yield Points - ⚡ Biggest Takeaways

  • Light's criteria differentiate transudative (e.g., CHF, cirrhosis) from exudative (e.g., infection, malignancy) effusions.
  • Tuberculous pleurisy typically presents as a lymphocytic exudate with elevated ADA (>40 U/L).
  • Malignant effusions are often hemorrhagic; cytology is key for diagnosis.
  • Empyema, pus in the pleural space, necessitates thoracentesis and often chest tube drainage.
  • Tension pneumothorax is a medical emergency requiring immediate needle decompression.
  • Mesothelioma is strongly linked to asbestos exposure and has a poor prognosis.

Practice Questions: Pleural Diseases

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Flashcards: Pleural Diseases

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Most common type of foregut cyst is _____ cyst

bronchogenic

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