Pleural disease

Question 1

Apical pleural cap

Answer 1

Cresenteric apical opacity <5mm thick Bilateral > unilateral Pathology: - Pleural thikcening/scarring ?chronic ischaemia?chornic traction from weight of lugns - Micro: hyaline fibrosis of visceral pleura. Collapsed by intact elastic framework. DDx: - Pancoast tumour - Pulmonary TB - Radiation fibrosis - Mediastinal hemorrhage - Extrapleural fat

Question 2

Plerual Plaques

Answer 2

Pathology:

• Eitiology: Occupational asbestos exposure most common
• 20-30 years post exposure
• Asbestos chrysotile thought to migrate to pleura causing inflammation/scarring
• ASsociation: pleural effusion
• Micro: Hyalinized acellular colalgen fibres in ‘basket weave’ pattern. Dystrophic calcification.

Imaging:

• Radiogrphy:
  
  • Multifocal, bilateral, nodular and discontinous pleural thickening
  • +/- calcifications
  • +/- incomplete border sign
• CT:
  
  • Multifocal, bilateral, nodular and discontinous pleural thickening
  • Calcificaitons 40-90%
  • Separate from chest wall by thin layer of extrapleural fat
  • Associations:
    
    • Rounded atelectasis (10%)
    • Unilateral plerual effusions
    • Asbestosis (fibrosis)
    • Diffuse plerual thickening

DDx:

• Extrapleural Fat
• Chest wall Trauma
• Pleural infection
• Pleural mets
• Priamry pleural neoplasm
• Talc pleurodesis
  *

Question 3

Solid pleural met

Answer 3

• Adenocarcinoma most common
• Lung (40%) > Breast (20%) > lymphoma (10%) > Unknown primary malignancy (10%) > ovarain/gastric cancer
• Lung Ca: nodular pleural thickening ipsilateral to primary site
• Breast Ca: pleural effusion > pleural nodules/mass
• Lymphoma: small effusions, pleural plaques/nodules/masses
• Thymoma: pleural plaques/noduesl/masses

DDx:

• Malignant mesothelioma
• Localised fibrous tumour of pleura
• Pleural fibrosis and fibrothorax
• Loculated pleural effusion

Question 4

Malignant Plerual Mesothelioma

Answer 4

Pathology:

• Eitiology: strong association with asbestos exposure
• Gross:
  
  • Parietal > visceral pleura
  • Right > left hemithorax
  • Masses coalesce into sheet-like or confluent pleural masses
  • mets >50% autopsy
• Micro:
  
  • Difficult differentiation between mesothelioma, metastatic adenocarcinoma, asbestos related pleural fibrosis, reactive pleural hyperplasia
  • MPM: greater nuclear atypia than adneocarincoma
  • 3 categories:
    
    • Epithelioids (60%): uniform cuboidal cells with eosinophilic cytoplasm, central nuceli and distinct nucleoli. Dififcult to distinguish from lung adeno
    • Sarcomatoid (12%): spindle cells with nuclear atypia. Difficult to distinguish from true sracoma
    • Biphasic (30%): elements of both

Imaging:

• Pleural effusion
• Nodular/lobular pleural thickening: circumferential + > 1 cm thick
• Volume loss
• Chest wall/mediastinal/diaphgramatic invasion
• Lymphadneopathy
• Calcifeid plerual plaques (25%)

Question 5

Localised fibrous tumour of Pleura

Answer 5

Pathology:

• Etiology: unknown. No associated carcinogens.
• Gross: well-marignated lobular mass +/- vascular pedicle +/- necrosis/hemorrhage/cystic degenration
• Micro:
  
  • Submesotheilal connective tissue origin
  • Low grade neoplasm
  • Patternless pattern (haphazardly arranged tumor cells)
  • Malignancy: high cellularity, pleomorphism, high mitotic rate

Imaging:

• Well defined peripheral nodule or mass
• mid to inferior hemithorax predilection
• +/- pleural effusion