Pleural pathology Flashcards
Causes of pleural inflammation
- Primary inflammatory diseases
- Infections - usually secondary to lung
- Pulmonary infarction
- Emphysema
- Pleural neoplasms
- Frequently there is pleural effusion
No pleural effusion =
pleuritic chest pain and pleural rub during breathing (on auscultation)
Pleural fibrosis Pathogenesis
Can prevent normal expansion and compression of the lung during respiration causing breathlessness, can form adhesions and obliterate the cavity
Pleural decortication =
removing fibrous tissue to improve respiration
Pleural fibrous plaques =
Markers of asbestos exposure
Parietal pleural fibrous plaques
- Associated with low level asbestos dust exposure
- Asymptomatic but may be visible on chest radiographs
Diffuse pleural fibrous plaques
- Associated with high level asbestos dust exposure
- Symptomatic - prevents normal expansion and compression of the lung during breathing causing breathlessness
Pathological fluids in the pleural cavity
- Pus = empyema or pyothorax – secondary to pneumonia
- Blood = haemothorax – trauma, ruptured thoracic aortic aneurysm
- Bile = chylothorax – usually trauma
Liquid/serous fluid in the pleural cavity =
Pleural effusion
Transudate PEs
- low protein and lactate hydrogenase
- Low capillary oncotic or high hydrostatic pressure
- High hydrostatic pressure = left ventricular failure, renal failure (backlog in pulmonary circulation); low oncotic pressure = hypoalbuminemia
Exudate PEs
- high protein and lactate dehydrogenase
- Pathological capillaries lose semi-permeability
- Caused by inflammation with/without infection e.g. pneumonia
Signs of pleural effusion
- dull to percuss, reduced breath sounds
- breathlessness, pleuritic pain
Treatment of PE’s
- Breathlessness = remove the fluid by aspiration – extreme cases = pleurodesis
- Treat the underlying cause = test pleural fluid (cytology and biopsy),
Gas/air in pleural cavity =
pneumothorax
Open pneumothorax
Chest wall perforation in trauma - external air is drawn into the pleural cavity during inspiration, reducing potential lung expansion
Closed pneumothorax
A lung perforation, usually not traumatic, connects the lung air spaces to the pleural cavity. Lung air is drawn into the pleural cavity during inspiration, reducing potential lung expansion
Tension pneumothorax
Open or closed pneumothorax may be valvular – lets air in during inspiration but nothing out in expiration. This may compress mediastinal structures – venae cavae, heart which then may compress the contralateral lung
Diagnosis of a pneumothorax
- Symptoms = breathlessness mainly
- Signs = cyanosis, trachial deviation
- Percussion = hyper-resonant; auscultation = reduced breath sounds
Treatment of pneumothorax
- Any = valvular aspiration (if tension (emergency) = aspirate with needle)
- Open = cover chest wound with occlusive adhesive dressing
- May resolve spontaneously, if recurrent = pleurodesis
Primary pleural neoplasm =
Malignant mesothelioma
Malignant Mesothelioma aetiology
- Asbestos – 80-90% of cases – MM develops 15 years to over 60 years after exposure
- Thoracic irradiation
- BAP1 (BRCA1-associated protein 1) mutations – uveal (eye) melanomas and mesotheliomas
Malignant Mesothelioma histology
- Tubulopapillary epithelioid and spindle cell sarcomatioid
- May also be desmoplastic = poorly differentiated
- To differentiate between MM and non-small cell carcinomas e.g. adenocarcinoma
Malignant Mesothelioma definition
- A neoplasm of mesothelial cells that line serous cavities - pleura, peritoneum, pericardium, tunica vaginalis
- More common in men
Malignant Mesothelioma types
- Early = can produce large pleural effusion, Malignant cells may be shed into the effusion
- Advanced = the mesothelioma can spread around the pleural cavity, although metastases are rare
Asbestosis
- Asbestosis is a usual interstitial pneumonia-like progressive pulmonary interstitial fibrosis caused by high level exposure to asbestos dust
- Impairs both gas exchange and lung expansion and contraction during breathing
Asbestos corns
benign hyperkeratotic wart-like skin lesions associated with asbestos exposure
