Pulmonary metastasis



Pulmonary metastasis generally refers to the deterioration of malignant tumors and metastasis to the lungs. The lung is the only place for systemic blood flow, and its abundant capillary bed is a high-efficiency filter, which is a good site for the metastasis of various malignant tumors. 20 to 54% of people who die of malignant tumors have lung metastasis, and 15% of the lungs are the only metastatic site. The occurrence of lung metastases is generally thought to be that the tumor cells stay in the bifurcation of the small arteries or capillaries of the lungs, adhere to the endothelium of the capillaries to form a clot, and pass through the wall of the tube into the connective tissue outside the blood vessels, and then the cells Hyperplasia becomes a small tumor forming a metastatic tumor.



First, lung metastasis is the most common blood metastasis, and the blood is transferred to the tumor cells through the vena cava to the right heart and transferred to the lungs. After the tumor plug reaches the pulmonary arterioles and capillaries, it can infiltrate and pass through the blood vessel wall. What are the causes of lung metastasis cancer? It grows in the surrounding interstitial and alveolar, forming lung metastasis. Lymphatic metastasis is mostly transferred from the blood to the pulmonary arterioles and capillary beds, and then invades the bronchial perivascular lymph nodes through the blood vessel wall. The cancer cells proliferate in the lymphatic vessels and form multiple small nodular lesions.

Second, when the metastatic tumor of the lung is small, there are few symptoms, especially hematogenous metastasis. It is rare to have blood in the cough and sputum. A large amount of lung metastases can cause shortness of breath, especially lymphatic metastasis.

Third, it often occurs in the perivascular interstitial, interlobular septum and subpleural stroma, and spreads in the lung through the lymphatic vessels. The primary disease in which the tumor directly metastasizes into the lung becomes a malignant tumor of the pleura, chest wall, and mediastinum.

Fourth, usually the disease is latent and progresses faster, and it quickly increases in a few weeks. Chest tightness or chest pain when pleural metastasis. Metastatic tumors in the lungs change rapidly, and tumors increase and increase in the short term, and some after primary tumor resection or after radiotherapy and chemotherapy. Sometimes it can be reduced or disappeared.


an examination

Related inspection

Pulmonary ventilation imaging CT scan

Because of the symptoms and signs of pulmonary metastases, the positive rate of tumor cells and bronchoscopy is low, so it should be emphasized that the original tumor cases, with or without lung symptoms, must be examined early in the chest, especially Thoracic thin-slice CT and MRI are performed on lesions located in the posterior part of the heart, at the apex of the heart, at the lung base or at the hilar site, and in the mediastinum, to determine whether there is a lung metastasis, and to clarify and identify whether the tumor is true or not. Metastases, with or without extrapulmonary metastases, in order to develop a treatment plan and assess prognosis.


Differential diagnosis

1, pleural metastasis: mainly from the lungs, followed by the breast, other common primary sites have stomach, ovary, pancreas and so on. Cancer causes pleural capillary pressure, colloid osmotic pressure, capillary permeability and intrathoracic pressure changes, resulting in pleural effusion - malignant pleural effusion. Malignant pleural effusion, also known as cancerous pleurisy, is a pleural effusion caused by cancer pleural metastasis and pleural cancer itself. Malignant pleural effusion is a common complication of advanced cancer. Once a pleural effusion occurs in a cancer patient, it means that the lesion has spread locally or in the body.

2, pericardial metastasis: refers to the results of other parts of the malignant tumor metastasis to the pericardium, pericardial metastases is one of the systemic manifestations of malignant tumors.

3, lymphatic metastasis: is the most common mode of metastasis of cancer, refers to the invasion of tumor cells through the lymphatic wall, after the fall off with the lymph fluid was brought to the lymph node of the confluence, and the same tumor as the center. Lymph node metastasis usually begins with the first set of lymph nodes closest to the tumor, and then to the distant distance. When the tumor cells infiltrate and grow at each station, they also spread to adjacent lymph nodes in the group. However, there are exceptions. In some patients, it is also feasible to bypass the lymph nodes in the pathway to directly transfer to distant lymph nodes. The mode of clinical transfer is called a jump transfer. These features increase the complexity of tumor metastasis, resulting in clinical lymph node metastasis that is difficult to find the primary lesion.

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