Malignant pleural mesothelioma
Malignant pleural mesothelioma ( MPM ) is a rare and aggressive malignancy arising from the mesothelial cells lining the pleural cavity ( Patel et al 2016 )
aggressive malignancy of the pleural surface associated with previous asbestos exposure insidious neoplasm long latent period after exposure to asbestos ranging from 20-70 yrs originates from mesothelial surfaces of the tissues of pleura but can also happen in the pericardium and tunica vaginalis most commonly affected is the pleural layer causing MPM amosite and crocidolite ( most tumorigenic ) – variants of asbestos are strongly associated with MPM risk depends upon the type of fibre that the individual was exposed to and the duration peak incidence in 5th and 6th decade of life male preponderance ( occupational nature of disease )
Risk factors -exposure to asbestos ( used widely due to fire-resistant properties ) professions associated with ship building, mining , ceramics , cement , auto parts particularly brake lining , paper mill , insulation , railroad repair smoking is not linked with MPM but smoking and asbestos exposure together would increase the risk significantly demolition work electricians , plumbers and launderers it is also thought that individuals with germline BRCA1 associated protein -1 ( BAP1 ) mutation may be predisposed to MPM – they can develop MPM without asbestos exposure ionising radiation ( mainly therapeutic )
world health issue due to poor prognosis and increasing incidence true incidence in countries still using asbestos as Eastern Europe , Asia , S America and most of Africa is not known rare cancer which poses diagnostic and therapeutic difficulties up to 20 % of the patients known to suffer from MPM have no prior exposure to asbestos and majority of the people exposed to asbestos do not develop the disease.
Mean latency between exposure to asbestos and developing the disease is 40 yrs for pleural and 46 yrs for peritoneal mesothelioma onset is often insidious and non-specific presentation can be with breathlessness , chest pain , cough ( non productive ) initial SOB is mostly due to pleural effusion and in later stages due to restricted respiratory movement and encasement chest pain may be due to the effusion or the tumor , bone pain due to rib invasion , neuropathic pain from intercostal nerve involvement presentation may be accompanied with fatigue , anorexia , weight loss , sweats and malaise Obtain a thorough occupational history covering all occupations throughout life Presentation can also be with extensive disease and complications ○ superior vena cava obstruction ○ cardiac tamponade ○ spinal cord compression ○ local compression ( if the oesophagus is compressed it can cause dysphagia ) ○ phrenic nerve or recurrent laryngeal nerve palsy ○ diaphragmatic dysfunction ○ Horner’s syndrome ○ severe chest wall pain due to tumor invasion Peritoneal involvement can cause ascites or bowel obstruction
pleural effusion may be present check for any palpable lymphadenopathy the disease is more common on the right side
CXR can show pleural effusion , loss of intrathoracic volume , nodular pleural thickening , irregular fissural thickening or a localised mass lesion Pleural plaques on CXR indicate serious exposure to asbestos Unilateral pleural effusion and plaques are the most common findings on CXR imaging as US /CT / MRI / PET scans can aid in diagnosis Chest CT with IV contrast optimised for pleural evaluation is the modality of choice for initial evaluation of patients with suspected MPM diagnosis can be challenging for pathologists -pleural fluid cytology ( via thoracentesis ) , needle biopsy of pleural fluid under CT , video-assisted thoracoscopy surgery and open thoracotomy may aid in diagnosis stepwise histological diagnosis which is supported by clinical and radiological findings – supplemented by immunohistochemistry
Differentials non-small cell lung cancer small cell lung cancer drug induced lung complications lung fibrosis benign mesothelial proliferations other pleural malignant tumors
management is complex – lethal cancer which is difficult to treat diagnosis is often made at an advanced stage no curative treatment for MPM prognosis is notoriously poor with a median survival time of 12 months after the diagnosis MPM is classified as an occupational disease Haematogenous spread of MPM can be to any organ Symptom management – palliative Treatment may involve a combination of surgery ,chemotherapy and / or radiotherapy Most patients receive platinum based chemotherapy with modest improvement in survival Surgery /multimodal therapy is offered to carefully selected patients Under investigation – targeted therapy , immunotherapy
occupational neoplasm mesothelioma sufferers in UK can claim for compensation they might be able to get industrial disablement benefit solicitors with specialist interest in mesothelioma claims can be found on asbestos support group websites as asbestosforum UK , asbestos awareness and support cymru coroner’s inquest is needed but this does not cause a delay in funeral as a temporary death certificate can be issued by the coroner while the results of the inquest are available ( MacMillan.org )
- Patel, Shivani C, and Jonathan E Dowell. “Modern management of malignant pleural mesothelioma.” Lung Cancer (Auckland, N.Z.) vol. 7 63-72. 3 May. 2016, doi:10.2147/LCTT.S83338
- Jain SV, Wallen JM. Malignant Mesothelioma. [Updated 2021 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519530/
- Mott, Frank E. “Mesothelioma: a review.” The Ochsner journal vol. 12,1 (2012): 70-9.
Malignant pleural mesothelioma: an update on investigation, diagnosis and treatment