Diffuse pleural mesothelioma

Introduction to diffuse pleural mesothelioma Diffuse pleural mesothelioma, formerly known as malignant mesothelioma, is a slow-lethal tumor. Although the incidence is not high, it is more common than localized pleural mesothelioma. It is the most common pleural tumor. Types of. Clinical manifestations are associated with invasive behavior, which usually locally invades the pleural cavity and surrounding structures. basic knowledge The proportion of illness: 0.001%-0.003% Susceptible people: between 40 and 70 years old Mode of infection: non-infectious complication:

Causes of diffuse pleural mesothelioma

(1) Causes of the disease

The causes and mechanisms of the disease are still not fully understood and may be related to the following factors:

1. Long-term exposure to asbestos is considered to be the main cause of the tumor. All types of asbestos fibers are related to the pathogenesis of mesothelioma, but the risk of each fiber is not the same. The most dangerous is exposure to blue asbestos. The least dangerous is exposure to yellow asbestos. The incubation period of the first exposure to asbestos is generally 20 to 40 years. The incidence of mesothelioma is directly proportional to the time and severity of exposure to asbestos. The pathology of asbestos is as follows:

(1) Animal experiment: Asbestos fluid can induce pleural mesothelioma.

(2) Asbestos fibers were found in malignant mesothelioma.

(3) Asbestos workers, especially those who work for 20 to 40 years, found that the incidence of mesothelioma was as high as 3.1%.

2. Other non-asbestos causes exposure to natural mineral fibers, chronic pleural cavity infection (tuberculous pleurisy) and repeated pulmonary infections. Cases of pleural mesothelioma after exposure to radiation have also been reported, from exposure to radiation to pleural mesothelioma. The time is 7 to 36 years, with an average of 16 years.

3. Sickle 40 (SV40) infection In patients without a history of asbestos exposure, 30% to 50% may be associated with SV40 infection. In the age of polio, millions of Americans may be vaccinated with Salk. The vaccine is infected with SV40. Recently, SV40 was isolated in patients with brain tumors and mesothelioma. Carbone and colleagues isolated SV40 fragments in 60% of patients with mesothelioma and successfully induced intracerebral injection of SV40 in rats. Mesothelioma.

(two) pathogenesis

1. The early visible lesions can be seen in the normal or opaque visceral or parietal pleura with numerous white or gray particles and nodules or thin plates. As the tumor develops, these nodules fuse with each other, grow, and the pleural surface becomes more and more The thicker, occupying the pleural cavity, encapsulating the lungs to make the volume smaller and smaller, and causing the affected chest wall to collapse.

2. The advanced tumor nodules of the lesion extend to the square, and continue to form a piece, which may involve the diaphragm, intercostal muscle, mediastinal structure, pericardium and contralateral pleura. Once the pericardium and mediastinum are involved, the patient may die from the tumor and the lung and lung. Restriction, 50% of autopsy patients found blood-borne metastases, but rarely mentioned in the clinic.

Mesothelioma originates from mesothelial stem cells, which can differentiate into epithelial or mesenchymal cells. Therefore, it is common to find both cells simultaneously in the same tumor. Histologically, diffuse or malignant mesothelioma Can be divided into three types: epithelial type, sarcoma (interstitial) type, mixed type.

The epithelium of epithelial tumor cells has various structures, such as papillary, tubular, papillary, banded or flaky, polygonal epithelial cells have many long and slender, surface-branched microvilli, desmosome, into The bundle of elastic filaments and intercellular spaces.

Fibrous cells resemble spindle fibroblastic sarcoma, which has a spindle-like, parallel configuration with egg-shaped or slender nuclei and good nucleoli development.

The hybrid type has both epithelial and fibrous structures. When a biopsy is taken from a tumor mass, the more specimens are taken from different parts, the more it is mixed.

Histopathological diagnosis of mesothelioma is difficult, and it is often necessary to identify adenocarcinoma and malignant pleural mesothelioma by special staining, immunohistochemistry, and electron microscopy.

Diffuse pleural mesothelioma prevention

There is no effective treatment for this disease, and early detection and early treatment is the key to prevention.

Diffuse pleural mesothelioma complications Complication

There is no complication of this disease.

Diffuse pleural mesothelioma symptoms Common symptoms Asphyxia pleural effusion shortness chest tightness chest pain dyspnea breathing sound weakening hypercoagulable state immune hemolysis dry cough

Males are more common, male to female ratio is about 2:1, 2/3 patients are 40 to 70 years old, about half of the patients have a history of asbestos exposure, slow onset, various clinical manifestations, epithelial and mixed pleura Mesothelioma is often accompanied by a large amount of pleural effusion, while the fibrous type usually has little or no pleural effusion. Epithelial patients seem to involve more clavicular or axillary lymph nodes and extend to the pericardium, contralateral pleura and peritoneum; There are distant metastases and bone metastases.

In the early stage of the disease, lack of specific symptoms, 60% to 90% of patients with dyspnea, chest pain, dry cough and shortness of breath, about 10.2% of patients may have symptoms of fever and general discomfort, 3.2% of patients with joint pain as the main symptoms, The patient often has a cough, mostly dry cough, no sputum or sputum, and no blood in the sputum. The symptoms of shortness of breath in patients with malignant pleural mesothelioma are obvious, especially after the activity, chest tightness, shortness of breath is obviously aggravated, and symptoms are relieved after rest. Dyspnea is secondary to pleural effusion, and the degree is aggravated with the increase of pleural effusion and tumor. The early effusion is free in the pleural cavity, and then gradually constricted, and finally gradually replaced the large tumor tissue, chest pain. At first, it was blurred and dull. When the tumor invaded the intercostal nerve, the pain was limited.

In the middle and late stage, 50% to 60% of patients show a large amount of pleural effusion, of which blood pleural effusion accounts for 3/4. Tumor tissue can envelop the lung tissue of the affected side, which makes lung recruitment limited. Patients with malignant pleural mesothelioma After treatment, the patient loses weight with severe shortness of breath, progressive failure, and finally suffocates due to extreme dyspnea. The chest pain of patients without massive pleural effusion is more severe, gradually increasing to the patient's unbearable, general analgesics difficult to relieve, pain often Occurred in the lesion, the diaphragm can be radiated to the upper abdomen, shoulder, no detailed history and physical examination, may be misdiagnosed as coronary heart disease, frozen shoulder or cholecystitis, some patients have periodic hypoglycemia and hypertrophic lung Osteoarthrosis, but these indications are more common in benign mesothelioma.

Patients with advanced stage manifested as debilitation, cachexia, ascites, and thoracic and abdominal malformations. The clinical manifestations were the result of progressive tumor invasion without effective control. In some patients, chest wall masses were found in the advanced stage of the disease, which were derived from mesothelioma. The thoracic cavity grows out, and may also be caused by needle implantation after thoracentesis.

Most of the physical examinations showed no positive signs in the early stage of the disease. Later, there were obvious pleural effusions. The chest was percussed with voiced sounds, the breath sounds were reduced, the mediastinum moved to the healthy side, etc., and the pleural mesothelioma grew very much, filling the entire pleura. In the cavity, the pleural effusion is less, the lung capacity is reduced, the chest wall of the disease side is collapsed, the intercostal space is narrowed, the mediastinum is pulled and moved to the affected side, and in some cases, abdominal distension may also occur. This clinical finding may indicate the tumor. Invasion of the abdominal cavity through the diaphragm, in the surgical sense, means that it can not be removed, once the diaphragmatic invasion occurs, 30% of patients can have intestinal obstruction.

In addition to the chest signs, patients may have tumor associated syndrome, although less common, but also in patients with mesothelioma, such as: pulmonary osteoarthrosis, clubbing (toe), abnormal secretion of vasopressin Signs (SIADH), autoimmune hemolytic anemia, hypercoagulable state, hypercalcemia, hypoglycemia and lymph node metastasis.

Diffuse pleural mesothelioma

Hemoglobin decreased, erythrocyte sedimentation rate increased, most patients with increased platelet count, platelet count up to 1000 × 109 / L, suggesting a poor prognosis, serum carcinoembryonic antigen is elevated in some patients, serum fetal protein is generally normal, serum IgG, IgA or IgM is elevated, the cause is still unknown, in addition to serum vasopressin increased, hemolytic anemia, hypercoagulable state, hypercalcemia, hypoglycemia and so on.

1. X-ray chest radiographs of the posterior anterior and lateral images of the chest can clearly show the pleural effusion of the affected side, which usually accounts for 50% of the side of the chest. About half of the patients except the pleural effusion can also see the pleura along the pleura. Multiple pleural masses with wavy growth and diffuse pleural nodular thickening may be associated with pleural calcification, which provides valuable clues for the diagnosis of malignant diffuse pleural mesothelioma, ipsilateral lung The tumor tissue was wrapped, the mediastinum moved to the side of the tumor, and the affected side of the chest cavity became smaller. In the late stage of the disease, the chest X-ray showed widening of the mediastinum, and the pericardial effusion caused the heart shadow to enlarge, showing soft tissue shadow and rib destruction.

2. Chest CT can show the size and extent of the tumor. It is very important to understand whether the tumor exceeds the ipsilateral thoracic border, invading the mediastinal structure, or invading the diaphragm and submucosal structure. The typical manifestation is: the chest of the affected side can be reduced, and the pleura is marked. Thickening, pleural effusion, pleural plaque can be seen in a few cases. In addition, chest CT can clearly show large irregular mass along the pleural surface. Some tumors grow along the interlobular fissure and extend into the mediastinum. After the posterior mediastinum grows into the contralateral thoracic cavity, some cases can still see nodules on the surface of the lungs, irregular calcification in the nodules, and finally dense calcified plaques and linear calcifications along the chest wall and the edge of the tumor on the chest CT. Chest CT sometimes shows that the tumor grows out of the bony thorax, destroying the ribs and the soft tissue of the chest wall.

3. MRI as a supplement to CT to determine the extent of the tumor and whether it can be removed, the sagittal image of MRI can clearly show the mediastinal and diaphragmatic invasion.

4. Thoracic wear is the first helpful diagnostic method. The pleural effusion of mesothelioma is mostly yellowish exudate. It is different from adenocarcinoma-related blood pleural effusion. The characteristics of diffuse mesothelioma pleural effusion are: Yellow or bloody, pH 1.020 ~ 1.030, Rivalta (+), a large number of normal mesothelial cells, well-differentiated or undifferentiated malignant mesothelial cells and different amounts of lymphocytes and multinucleated white blood cells, if the tumor volume is huge, pleural effusion The blood sugar level and pH may decrease, hyaluronic acid in pleural effusion>0.8mg/ml, serum hyaluronic acid is also significantly higher than normal (54g±28)g, and up to (287±282)g, therefore The pleural effusion is thicker.

5. Biopsy In some cases, cytological examination can confirm the diagnosis, but in most cases, pleural biopsy is needed. Closed pleural biopsy has been applied for a long time. It only makes sense when it is positive, because sometimes it is not good. As a result of false negative results, chest wall incision pleural biopsy should be the preferred method, because it can ensure that the biopsy specimens get a sufficient amount of tissue, the damage to the patient is not large, it is important to limit the surgical technique to 1 or 2 incisions, which is important. Instead of VATS, it is a thoracoscopic biopsy. The surgical incision should use the same incision as the future surgery, so that the hole can be removed during the operation to avoid the recurrence of the tumor in the site. The pleural cavity is closed during surgery, and the thoracoscopic can not be placed. Common, in this case, should be converted to open chest pleural biopsy.

Diagnosis and diagnosis of diffuse pleural mesothelioma

Diagnostic criteria

According to the patient's medical history, there may be a history of asbestos exposure. The physical examination found that the breath sounds are weakened and the percussive dullness indicates pleural effusion or tumor growth. In the advanced stage, the chest wall is observed and palpated, especially the intercostal space, and the tumor can be found to bulge, suggesting that the tumor invades the chest wall. Combined with laboratory examination and chest CT examination to determine whether pleural calcification or bone structure is damaged, the possibility of malignant pleural mesothelioma should be considered, but in order to confirm the diagnosis, it still needs to be further confirmed by pleural effusion examination and pleural biopsy. The biopsy diagnosis rate of video-assisted thoracoscopic techniques can reach 100%, and the risk of surgery and mortality are low, which can replace the thoracotomy biopsy.

Although pleural effusion cell smears, thoracic pleural biopsy and pleural effusion cell block biopsy can make a malignant diagnosis, but can not identify pleural metastatic adenocarcinoma and malignant mesothelioma, mainly by light microscopy, electron microscopy, histochemistry, immunity Methods such as histochemistry and hyaluronic acid determination were distinguished from pleural metastatic adenocarcinoma.

There are three techniques for the diagnosis of malignant mesothelioma. The periodic acid-Schiff solution is used for histochemical staining. The keratin and carcinoembryonic antigens are used for immunoperoxidase assay and electron microscopy. For these tests, biopsy specimens must be fixed immediately with neutral formalin solution, and another small tumor biopsy specimen is destined for use in glutaraldehyde solution for electron microscopy.

1. Periodic acid-Schiff staining (PAS) is the only reliable histochemical method that can distinguish malignant pleural mesothelioma from adenocarcinoma. Although the characteristics of various metastatic adenocarcinomas are different, they appear after amylase digestion. Strong positive vacuoles can be diagnosed as adenocarcinoma rather than malignant pleural mesothelioma.

2. The immunoperoxidase technique uses an antibody to act on keratin and carcinoembryonic antigen (CEA) to immunosuppressive staining of carcinoembryonic antigen, and the staining of malignant pleural mesothelioma is generally light or non-staining. On the contrary, adenocarcinoma staining is moderate and very concentrated. In addition, the study of keratin with immunoperoxidase also shows that there is a significant difference between mesothelioma and adenocarcinoma. Eight markers have been found for identification: tumor consolidation Glycoprotein 72 (B72.3), Leu-Mi, Vi-mentin, thrombomodulin, mucin component, cancer antigen 125 and diiodohydrin Schiff and amylase, carcinoembryonic antigen positive for adenocarcinoma 100% Specificity and sensitivity, because carcinoembryonic antigen test often has false negative, it is best to use 2 tumor markers, generally using CEA and B72.3, such as positive for both adenocarcinoma with 100% specificity and 88% Sensitivity; if both are negative, 100% specificity and 97% sensitivity to mesothelioma.

3. Electron microscopy examination of malignant pleural mesothelioma is different from lung, breast cancer and adenocarcinoma of upper gastrointestinal origin. The microvilli of its surface is thin and long, with branches, and the tension silk is rich, and there are no small roots of microvilli. And patchy; metastatic adenocarcinoma derived from the ovary and endometrium has intrinsic tissue deformation, including abundant mucin droplets, large amounts of cilia, dense nuclear particles, these changes are not present in mesothelioma, gland The fluff of the cancer is short and thick.

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