Epidemiology and Etiology
Malignant pleural mesothelioma (MPM) is an uncommon malignant disease with no standardized treatment and it doesn’t have any kind of prognosis. For the first time in 1937, Klemperer and Rabin classified mesotheliomas as local and diffuse. Stout and Murray identified these tumors histologically in 1942. In 1960, Wagner and his colleagues stated that the disease appeared in people who lived in places with intense asbestos contact in South Africa. After this date, the relationship between the contact with asbestos and the formation of mesothelioma has been proven by numerous studies.
Asbestos is not a single mineral. It is the name given to the fibrous hydroxy silicate family. Mainly, it is examined in two groups;
- Serpentine (Chrysolite-white asbestos)
- Amphibole (Crocidolite, blue asbestos, amosite).
White asbestos is a species of asbestos used in industry. The removal and the use of other asbestos species are prohibited. The most associated type of asbestos amphibole with MPM is crocidolite asbestos.
Eronite is considered as the strongest carcinogen.
It is reported that there are about 1,000 new cases each year in the UK: The incidence is 22 cases/1 million population/year. In populations which have no contact with asbestos, the expected incidence of 1 in 1 million people is up to %10 in lives with excessive contact.
- Pleural Scars.
- Spontaneous tumor development.
- Possible Simian virus 40 (SV 40) infection plays a role in etiology.
- Symptoms of Malignant Pleural Mesothelioma (MPM)
- Pleuritic chest pain
- Constitutional weight loss
- Night Sweating
- Abdominal Pain
- Shoulder Pain
- Dry cough
- Mass on the chest wall
- Metastatic tumor-related swallowing difficulty
- Early physical exemination findings in malignant pleural mesothelioma
- Pleural effusion findings
- Volume loss of frozen hemithorax, Frozen chest, Abdominal Mass
- Tumor implantation at the site of intervention
- Rare Findings
- Horner’s Syndrome
- Vena Cavas Superior Syndrome
- Drumstick Fingers
- Hypertrophy of hemithorax
- Spontaneous hemothorax findings
Radiologic findings in malignant pleural mesothelioma (MPM) are evaluated via direct chest radiographs (PA thorax and lateral graphs), computed tomography(CT), ultrasonography, PET-CT and MRI.
CT findings in MPM
Pleural effusion (massive/loculated), calcific pleural plaque, pleural thickening, pleural nodules, counter hemorrhoids, massive pleural thickening, irregular pleural surface, mediastinal pleural thickening, inter-lobular pleural thickening or mass, palpable plaque, costal destruction, fissure thickening in the opposite hemithorax, round atelectasis, hemi-thoracic hyperthrophy, vertebral corpus destruction, pneumothorax.
Mesotheliomas originate from mesothelial/or subserosal cells.
Mesotheliomas are examined in 3 basic histological types according to WHO classification.
- Epithelial Type
- Sarcomatoid (monophasic fibroblastic, sarcomatous, mesenchymal) type 3. Mix epithelial-sarcomatoid (biphasic) type
The first diagnostic method must be thoracentesis in pleural effusion cases. In the cytological examination of the inguinal intrapleural fluid, malignancy can be detected in 30-50% of cases. With percutaneous pleural biopsy, a positive result can be obtained in 1/3 of cases. Pleural biopsy can be performed in blinding style, better on CT coexistence. —
If any kind of result can not be obtained via these methods, open biopsy methods( VATS, thoracotomy) can be used. VATS is the golden standard especially in the early stage of MPM.
Prognostic factors that have a positive effect on survival in MPM are;
- Epithelial type,
- With age < 50,
- Sex is female,
- There must be no dsypnea and no weight loss,
- The number of platelets < 400.000,
- No contact history of asbestos and erionite,
- Having a high performance score,
- Early diagnosis and surgical resection of the tumor
Treatment Methods in Malignant Pleural Mesothelioma
- SURGICAL TREATMENT
- NEW TREATMENT METHODS
- PALIATIVE TREATMENT METHODS
Surgery, chemotherapy and radiotherapy can be used separately or together in the treatment of MPM. To relive or to reduce the symptoms of the patient, the aim of surgical treatment is to treat as much tumorous tissue as possible,
In the cases of MPM, it is appropriate to seek the answer to the following questions in the planning of treatment.
- Is the patient operable?
- Are there any findings such as intra pleural fluid, pleural thickening?
- Must thoracentesis be performed? Is it necessary to do a pleural biopsy?
- If pleural biopsy is performed, should biopsy localization/localizations be administered with radiotherapy?
- At what stage is the patient pre-operative? Is mediastinoscopy necessary?
- Is the planned operation radically qualified? Is it for palliation?
- Must neo-adjuvant and/or adjuvant chemotherapy be administered to the patient?
- What can be done for the palliation symptoms?
Today, the treatment of MPM is multidisciplinary as it is in lung cancer. In only 1-5% of cases with MPM, radical surgical treatment is possible.
The recognition of ephitelial type is required in MPM for surgical treatment. Experience in the surgical center or in the surgical team is required. It must be known that the surgeon is only a part of the cure, and that the multi-modal treatment experiences are limited.
As Surgical Treatment Methods;
- Pleurectomy/ Decortication; In the early stages, the entire tumor can be removed.
- Extrapleural pneumonectomy (EPP); It can be performed if visceral pleural tumor is common, or if the pleural cavity is obliterated.
These surgeries are performed during stage I and stage II. Presence of mediastinal lymph nodes, mediastinal spread, invasion of diaphragm, sarcomatoid or mixed histology affect prognosis negatively.
The mortality of pleurectomy is less than 5%. Median survival ranges from 9 to 21 months. In EPP, the operative mortality ranges between 5-7,5% and the 2-year of survival time ranges between 20% to 58%.
Survival rates in all patients are 36% for 2 years and 14% for 5 years.
Epithelial type tumors have 2 year survival rate of 52% and 5 years of 21%. 2-Year survival in sarcomatous or mixed types is 16%, and the survival rate of 5 years is 0%.
Extrapleural nodal involvement is a negative prognostic factor. In patients without nodal involvement, a 2-year of survival is 42% and a 5-year of survival is 17%. On the other hand, patients with extranodal involvement have a 2 -year survival rate of 23% and a 5-year survival rate of 0%.
In patients with negative surgical margins, a 2-year survival rate is 44% and a 5-year survival rate is 25%. On the other hand, in patients with positive surgical margins, a 2-year survival rate is 33%, a 5-year survival rate is 9%.
Surgical marginal negative, non-extranodal, 31 cases of epithelial type patients have a survival of appr. 51 months and 2 years is 68%, a survival of 5 years is 46%. (Sugarbaker DJ,1999).
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