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



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.



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.
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 ?
0 criteria, bone metastases were not accepted as target lesions because they are non-measurable.
But that may overlook important differences between brain metastases from different types and sites of cancer for example, lung cancer, breast cancer, or malignant melanoma.
Metastases from internal malignancy are thought to occur from a variety of methods including direct extension, via lymphatic spread, hematogenous spread and from iatrogenic seeding during colon resection.
We previously reported (31) that B16-BL6 melanoma cells form brain metastases in approximately 25% of mice following the injection of tumor cells into the footpad of syngeneic C57BL mice.
The postoperative course was uncomplicated, and the patient is currently under follow-up with no newly detected metastases.
Annualized global bone metastases market revenues data from 2005 to 2010, forecast for seven years to 2017.
Following surgery the patient was referred to Orthopaedics for surgical resection of the solitary right iliac wing bone metastases lesion with radioactive-iodine therapy to follow.
The use of peri-operative chemotherapy in patients with liver-only metastases is used in two clearly defined treatment settings.
6% of the patients in the treatment group developed symptomatic brain metastases compared with 40.
Conversely, there is a relative paucity of data concerning metastases to the colon and rectum during life.
Metastases to the digits may initially arise in bone, before enlarging locally to invade skin, or arise in skin first (3).