Mesothelioma_Flashcards
Definition
Malignant mesothelioma is an aggressive epithelial neoplasm arising from the lining of the lung, abdomen, pericardium, or tunica vaginalis. Asbestos exposure is the principal cause.
Pathophysiology
Asbestos fibers cause chronic inflammation, DNA damage, and eventual malignant transformation. Key mutations include BRCA1-associated protein-1 (BAP1) and NF2 genes.
Epidemiology
Annual incidence in the US is approximately 3200 cases. It predominantly affects older adults (60-85 years) and is more common in men (3:1 male-to-female ratio).
History
Patients often present with shortness of breath, chest pain, fatigue, or dry cough. A history of asbestos exposure is common, with a latency period of 20-40 years.
Examination
Examination findings may include diminished breath sounds, dullness to percussion, or signs of pleural effusion. Constitutional symptoms like weight loss and fatigue are common.
Investigations - Bedside
Thoracentesis and pleurodesis may provide diagnostic clues and symptomatic relief.
Investigations - Bloods
Routine blood work shows baseline organ function. Elevated platelet count or anemia may suggest advanced disease.
Investigations - Imaging
Chest X-rays reveal pleural thickening or effusion. CT scans can detect pleural abnormalities and lymph node involvement.
Investigations - Special Tests
Biopsy via video-assisted thoracoscopy is the gold standard. Immunohistochemical markers like calretinin confirm the diagnosis.
Management - Conservative
Smoking cessation and workplace safety education are crucial preventive measures.
Management - Medical
Chemotherapy (cisplatin + pemetrexed) and immune checkpoint inhibitors (nivolumab + ipilimumab) are mainstays of treatment for inoperable cases.
Management - Surgical
Surgical options include extrapleural pneumonectomy (EPP) or pleurectomy with decortication for selected operable patients.
Risks of Treatments
Chemotherapy can lead to hematological toxicity. Radiation therapy risks include pneumonitis and skin erythema.
Benefits of Treatments
Chemotherapy improves survival and quality of life. Palliative interventions relieve symptoms like dyspnea.
Medical and Laboratory Sciences
Biomarkers such as soluble mesothelin-related peptides (SMRP) may aid diagnosis and prognosis.