Several ways of tumor metastasis?

summary

Tumor metastasis refers to the process that malignant tumor cells from the primary site, through lymphatic, vascular or coelomic pathways, to other sites to continue to grow. This characteristic of malignant tumor should be called diffusion. The metastasis of malignant tumor is often the main reason for the failure of tumor treatment. Benign tumors have no metastasis. Malignant tumors are prone to metastasis. What are the specific ways of tumor metastasis?

Several ways of tumor metastasis?

Lymphatic metastasis; Malignant tumor, especially cancer, is the most common way of metastasis. Lymph node metastasis is more common in tumors (cancers) of epithelial origin. There are many lymphoid tissues in the human body, and the lymphatic vessels are distributed all over the body. Their main function is to collect the lymphoid fluid formed by the interstitial fluid of the whole body, so that tumor cells are easy to immerse; Lymph node is the most common metastatic site of tumor, which can filter lymph and release immune cells. Under certain conditions, tumor cells infiltrate into lymphatic vessels, survive in lymphatic vessels and are transported to lymph nodes, then stay and proliferate to form metastatic foci. After the tumor cells grow and propagate in the lymph nodes, they can continue to metastasize to other distant lymph nodes. For example, breast cancer first metastasizes to the ipsilateral axillary lymph nodes, lung cancer first metastases to the hilar lymph nodes, and then from this group of lymph nodes to the next group of lymph nodes, forming extensive lymph node metastasis. When lymph node metastasis occurs, it is often enlarged and hardened, and the lymph nodes on the body surface can be touched by physical examination.

Hematogenous metastasis; It refers to the spread of tumor cells to distant organs of the whole body through blood circulation, which is common in advanced cancer, as well as fast-growing and highly malignant tumors; Sarcomas, tumors with more thin-walled vessels or blood sinuses also have blood metastasis. Most of the malignant tumor cells infiltrate into the surrounding area, penetrate the basement membrane and vascular wall, and enter the blood circulation. But most of these cells will be recognized and killed by the body's immune system, and only a few survive and proliferate to form metastatic foci. When tumor cells enter the blood, they can infiltrate and penetrate vascular endothelial cells, or they can develop from lymphatic metastasis. Through systemic blood circulation, tumor cells often metastasize to liver, lung, bone, brain and other parts. Most of the metastatic lesions grow at the edge of the metastatic organs, forming many multiple metastatic cancer nodules with similar volume and spherical shape

Planting transfer; Also known as transplant metastasis, it is another common way of metastasis of malignant tumor besides lymphatic and blood channels, and the most common one is in abdominal cavity. After the tumor cells break through the serosa of the organ, they can fall off into the chest or abdominal cavity and spread to the surface of the adjacent organs, where they attach, plant and grow, thus forming many small secondary cancer nodules. Peritoneum is the most common site of implantation metastasis in serosa. For example, gastric cancer cells that break through serosa can fall off to the surface of ovary and cause ovarian metastasis. In addition, liver cancer and ovarian cancer often cause implantation metastasis on the surface of peritoneum. It is a common cause of Cancerous Pleural Effusion and ascites

matters needing attention

Planting transfer can also occur due to external factors. If the operation is not gentle, the tumor will be destroyed and the cancer cells will fall off, which may cause implantation metastasis. This kind of transfer is called iatrogenic implantation. Iatrogenic implantation is a problem worthy of attention in tumor surgery, but its influencing factors and probability need to be further studied.