- 1. The shifting of a disease or its local manifestations, from one part of the body to another, as in mumps when the symptoms referable to the parotid gland subside and the testis becomes affected. 2. The spread of a disease process from one part of the body to another, as in the appearance of neoplasms in parts of the body remote from the site of the primary tumor; results from dissemination of tumor cells by the lymphatics or blood vessel s or by direct extension through serous cavities or subarachnoid or other spaces. 3. Transportation of bacteria from one part of the body to another, through the bloodstream (hematogenous m.) or through lymph channels (lymphogenous m.). SYN: secondaries (1). [G. a removing, fr. meta, in the midst of, + stasis, a placing]- biochemical m. the transportation and induction of abnormal immunochemical specificities in apparently normal organs.- calcareous m. the deposit of calcareous material in remote tissues in the event of extensive resorption of osseous tissue in caries, malignant neoplasms, and so on.- hematogenous m. m..- in-transit m. in melanoma, a metastatic deposit occurring in the lymphatic pathway between the primary tumor and its draining lymph node s.- lymphogenous m. m..- pulsating metastases metastases to bone, usually from hypernephromas, but occasionally from thyroid tumors; considerablee vascularity may have expansile pulsation and a continuous bruit.- satellite m. m. within the immediate vicinity of a primary malignant neoplasm; e.g., skin adjacent to a melanoma.
* * *1 a) change of position, state, or formb) the spread of a disease-producing agency (as cancer cells or bacteria) from the initial or primary site of disease to another part of the body <metastases of breast cancer to bone (Medical Physics)> also the process by which such spreading occurs2) a secondary malignant tumor resulting from metastasis
* * *n.the distant spread of malignant tumour from its site of origin. This occurs by three main routes: (1) through the bloodstream; (2) through the lymphatic system; (3) across body cavities, e.g. through the peritoneum. Highly malignant tumours have a greater potential for metastasis. Individual tumours may spread by one or all of the above routes, although carcinoma is said classically to metastasize via the lymphatics and sarcoma via the bloodstream.• metastatic adj.
* * *me·tas·ta·sis (mə-tasґtə-sis) [meta- + Gr. stasis stand] 1. the transfer of disease from one organ or part to another not directly connected with it. It may be due either to the transfer of pathogenic microorganisms (e.g., tubercle bacilli) or to transfer of cells, as in malignant tumors. The capacity to metastasize is a characteristic of all malignant tumors. 2. pl. metastases. A growth of pathogenic microorganisms or of abnormal cells distant from the site primarily involved by the morbid process. metastatic adj
Medical dictionary. 2011.