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 ?
Tarao, "A case of hepatocellular carcinoma with portal invasion and right adrenal gland metastasis showing marked contraction of primary tumor and metastasis with treated by UFT alone," Japanese Journal of Cancer and Chemotherapy, vol.
Most of the cases mentioned in the literature till date found to have lytic bone metastasis or mixed lytic sclerotic bone metastasis with primary pulmonary adenocarcinoma.
Wide excision of the mass, often coupled with radiation, has also been linked with pain control in addition to prolonged survival after muscle metastasis diagnosis [4, 19, 22].
Investigation showed right proximal tibial metastasis with invasion of the patellar tendon.
Berkmen, "Penile metastasis from other malignancies: a study of ten cases and review of the literature," Urologia Internationalis, vol.
Skin metastasis is a complex process whereby tumor cells acquire the necessary biological properties enabling them to invade it from the primary lesion.
Bonifati, "Subacute onset of deafness and vertigo in a patient with leptomeningeal metastasis from ovarian cancer," Neurological Sciences, vol.
The exact mechanisms involved in esophageal metastasis from HCC are still unknown; however, several possibilities have been proposed.
Metastasis to the thyroid gland occurs as a direct spread in the head and neck region (pharynx, larynx, trachea, and esophagus) tumors and is mostly squamous cell carcinoma (8).
Tumor features and their relation to sublingual lymph node metastasis are not clearly defined; however, this relation is better defined in oral tongue cancer.
Metastasis cancer spread to different parts of the body from where it has started.
Observation indexes: The clinicopathological data of the patients with early gastric cancer were collected, including sex, age, and maximum diameter of cancer, tumor site, and depth of invasion, degree of tissue differentiation, lymph node metastasis and lymphatic infiltration.