metastasis


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Related to metastasis: bone metastasis

metastasis

1. Pathol the spreading of a disease, esp cancer cells, from one part of the body to another
2. a rare word for metabolism

Metastasis

 

a secondary pathological focus arising from the transfer of a pathogenic principle (tumor cells, infectious agent) from the primary site of affection by the lymph or blood.

In the modern view, the term “metastasis” generally applies to the spread (dissemination) of malignant tumor cells; the spread of an infectious principle is usually described by the term “metastatic infectious focus.”

Benign tumors are also known to metastasize, and the capacity to do so is inherent in normal cells of various origin (in placental villi, adipose and hematopoietic bone-marrow cells). A distinctive feature of metastasizing tumor cells is the uncontrollable growth of the metastasis, relating it to primary foci of malignant growth. Metastatic tumor nodes retain other properties of primary tumors as well, such as microstructural features and the capacity to form the same products; however, metastatic nodes often have a more primitive structure and consist of functionally less mature cells than do the original tumors.

When tumor cells spread chiefly through the lymphatic vessels, metastases generally appear in the lymph nodes closest to the primary site. Although much research has been devoted to the routes and anatomical patterns of lymphogenous metastasis, the biological patterns of formation of lymphogenous metastases remain obscure. The mechanisms of hematogenous metastasis (to the lungs, liver, bones, and other viscera) are better understood. Four stages in the development of hematogenous metastasis are distinguished: (1) the detachment of cells from the primary tumor node and their penetration of the blood through the vascular wall; (2) the circulation of the tumor cells in the blood; (3) the attachment of the cells to the vascular wall and the start of intravascular growth; and (4) the rupture of the vascular wall by the tumorous masses and the subsequent growth of the metastasis into the tissue of the affected organ. The presence of metastasis indicates that a tumorous process has shifted from a local growth phase to a phase of generalization. A distinction is made between solitary metastasis, which generally can be removed surgically, and multiple metastases, which require combined treatment using radiation and chemotherapy.

N. S. KISELEVA

metastasis

[mə′tas·tə·səs]
(medicine)
Transfer of the causal agent (cell or microorganism) of a disease from a primary focus to a distant one through the blood or lymphatic vessels.
(physics)
A transition of an electron or nucleon from one bound state to another in an atom or molecule, or the capture of an electron by a nucleus.
References in periodicals archive ?
Colonic adenocarcinoma presenting as a cutaneous metastasis in an old operative scar.
An expanding body of evidence suggests that the organ microenvironment also plays a critical role in dictating the outcome of metastasis and in determining tumor responsiveness to therapy (18,25).
The frequency of colorectal metastasis from breast carcinoma, in a necropsy series, is reported to range from 8% to 12%, (10) and in their series of a 15-year period, Taal et al (11) observed the same number as our study (17 patients) with breast carcinoma metastatic to the colon, rectum, or both.
Typically, the substances acted epigenetically, which is to say they turned metastasis suppressor genes on or off.
Squamous Cell Lung Cancer with Solitary Subungual Metastasis.
US, said: "Prostate cancer patients who develop bone metastasis usually have
Prognostic factors and the therapeutic strategy for patients with bone metastasis from differentiated thyroid carcinoma.
It is the fourth step that gives the crucial signal for the development of a clinically relevant metastasis.
If patients can be better classified as either low risk or high risk for metastasis, therapies can be custom tailored to patients, preventing over-treatment or under-treatment of the disease," adds first author Dr.
The breast cancer metastasis suppressor 1 (BRMS1) is a nuclear protein that regulates a number of genes, and suppresses metastasis without blocking growth in various human and mouse cancer cell lines.
The patient in this case report developed a metastasis in the vertebra and epidural space at the site of recent epidural catheterisation.