Malignant pleural mesothelioma
๐ซ Mesothelioma encasing the lung โ classically a malignant pleural tumour strongly linked to asbestos exposure.
๐ About
- ๐ฌ Malignant pleural mesothelioma (MPM) is a rare but aggressive tumour of the pleura.
- ๐งฑ Strongly associated with asbestos exposure (occupational in 70โ80%).
- โ ๏ธ Long latency (20โ50 years) between exposure and disease.
- ๐ฌ Smoking increases risk when combined with asbestos.
โ๏ธ Aetiology
- โฃ๏ธ Direct or indirect exposure to asbestos dust (shipbuilding, insulation, construction).
- ๐ญ High-risk industries: shipyard workers, construction, asbestos miners.
- Family members may be exposed indirectly (dust on work clothes).
๐งโโ๏ธ Clinical Features
- ๐ซ Thoracic: chest pain, pleuritic pain, dyspnoea, cough, weight loss, recurrent pleural effusions.
- ๐ Abdominal (peritoneal mesothelioma): pain, ascites, abdominal masses, weight loss.
- โค๏ธ Pericardial: chest pain, dyspnoea, pericardial effusion, arrhythmia.
- General: fatigue, cachexia, anorexia.
๐ฌ Investigations
- ๐งช Bloods: FBC, U&E, LFTs, ESR (nonspecific).
- ๐ฉป CXR: pleural effusion, pleural thickening, asbestos plaques.
- ๐ CT chest: defines pleural masses, chest wall/mediastinal invasion, staging.
- ๐งด Pleural fluid cytology: often nondiagnostic.
- ๐ Pleural biopsy: gold standard for histological confirmation.
๐ Management
- ๐ช Surgery: Extrapleural pneumonectomy (EPP) or pleurectomy/decortication in selected fit patients (usually combined with chemo ยฑ radiotherapy).
- ๐ Chemotherapy: platinum analogues + pemetrexed (first-line). Improves survival and symptom control. Other agents: raltitrexed, doxorubicin.
- โข๏ธ Radiotherapy: palliative role for pain and symptom relief; may be adjuvant post-op.
- ๐คฒ Palliative care: repeated pleural drainage, indwelling pleural catheter, pain control, psychosocial support.
๐ Prognosis & Clinical Pearls
- โณ Median survival: ~9โ18 months from diagnosis.
- โ ๏ธ Often presents late; cure is rare.
- ๐ Key OSCE pearl: pleural tumour in an older man with asbestos exposure โ think mesothelioma.
- ๐ก Histology types: epithelioid (better prognosis), sarcomatoid (worse), biphasic (mixed).
- โ๏ธ Distinguish from benign asbestos-related pleural disease (plaques without invasive tumour).
๐ References
๐งพ Clinical Case Examples โ Mesothelioma
Case 1 โ Occupational Exposure ๐ทโโ๏ธ
A 68-year-old retired shipyard worker presents with progressive shortness of breath, dull right-sided chest pain, and weight loss.
Exam: reduced breath sounds and stony dullness to percussion over the right lower chest.
Chest X-ray: large unilateral pleural effusion.
Pleural aspiration: exudative, cytology inconclusive.
๐ Diagnosis: Likely malignant mesothelioma (confirmed on VATS biopsy).
๐ Key points: Strong asbestos exposure history, unilateral effusion, poor prognosis.
๐ Management: Palliative โ pleurodesis for effusion control, chemotherapy (pemetrexed + cisplatin), symptom management.
Case 2 โ Chest Wall Invasion ๐ซ
A 72-year-old man with past asbestos insulation work presents with severe chest wall pain, breathlessness, and fatigue.
Exam: palpable hard mass over the left lateral chest wall, reduced chest expansion, clubbing.
CT thorax: irregular pleural thickening encasing the lung, with invasion into chest wall muscles.
Histology from pleural biopsy: epithelioid mesothelioma.
๐ Key points: Advanced disease with local invasion, chest pain dominant symptom.
๐ Management: Palliative care โ analgesia (including nerve blocks), radiotherapy for pain, chemotherapy considered if fit.