The metastases of malignant tumors

The metastases of malignant tumors is the most important indicator of malignancy tumor process that determines the course of the disease and the fate of the patient. The vast majority of tumors are more likely to spread to regional lymph nodes; in the later stages of the disease hematogenous metastases are found in the lungs, liver, bones and other organs. In some cases of malignant tumors of distant metastases develop at small sizes primary node, sometimes not yet captured clinical-radiological examination methods. In some cases metastases are found only in a few years after radical surgery for cancer of the breast, colon, and other (latent or dormant, metastasis).
The intensity of metastasis (the rate, the prevalence of metastases) varies and can depend on the grade of the tumor, and biological characteristics and status of its bearer. On metastasis affects the sum of many factors: the degree of malignancy of the tumor, its structure, level of differentiation (anaplasia), activity destroyuser infiltrating growth, invasion of cancer cells in the venous capillaries, amoeboid motility and loosening of the ties of cancer cells among themselves, lack of calcium ions, enhanced function enzymes (hyaluronidase), physiological mobility of the body (for example, language, lung, stomach and other). Of great importance in strengthening metastasis ascribe also a breach or weakening of protective immune mechanisms of the body of the patient.
There are metastases lymphogenous, hematogenic, mixed, implantation. Lymphogenous M. occur when cancer cells with the growth of the tumor penetrate into lymphatic vessels and are carried by the flow of lymph (forward) in the sinuses regional lymph nodes, where at first they are deactivated, and then gradually replace the tissue lymph node. Much less tumor cells block the lymph nodes, which leads to the back-flow of lymph and formation of the so-called retrograde M (for example, the metastasis of gastric cancer or ovarian cancer in supraclavicular lymph nodes; M gastric cancer in the ovary is a growth of Kruckenberg and others). Was observed at the film was recorded metastasis through direct communication between the lymph nodes and veins. The presence of lymphogenous M worsens the remote results of treatment of tumors.
Hematogenous M. occur more often in direct germination of tumor cells in blood capillaries or when introducing them to blood during surgery, diagnostic procedures, and if tumor cells through the thoracic duct reach subclavian veins. Metastasis in serous cavities characteristic of a cancer of a stomach (for example, the so-called metastasis of Shnitzler in dopasowa space, small multiple metastases, scattered all over the peritoneum).
Implant M arise due to the direct transfer of cells during the surgical removal of some tumors, for example after excision of papillary tumors of the bladder, ovaries, on the place of the drainage in contraparte after mastectomy. All this requires a physician careful observance of the principles of ablation (see) oncological operations.
Not all tumor cells trapped in the blood flow can cause Meters; most of them perish. Recently tried to install the forecast based on the discovery of cancer cells in the circulating blood. This method is not widely spread, but some authors consider that the discovery in the early operations in circulating blood cancer cells worsens the prognosis.
The structure of metastases, usually repeats the structure of the primary tumor, but the cellular atypism and anaplasia in M usually are more pronounced. However, sometimes in solitary M differentiation more apparent than in the primary node. Sometimes M. mistaken for primary tumor (for example, if an unrecognized lung cancer, ovarian; M in the bones with renal cell cancer and other).
Localization M has its own laws. So, bone sarcoma often give Meters into the lungs; cancer of the breast, prostate and thyroid glands especially often more likely to spread to the bones; lung cancer often spreads to the liver and the brain.