- A connective tissue neoplasm, usually highly malignant, formed by proliferation of mesodermal cells. [G. sarkoma, a fleshy excrescence, fr. sarx, flesh, + -oma, tumor]- alveolar soft part s. a malignant tumor formed of a reticular stroma of connective tissue enclosing aggregates of large round or polygonal cells; occurs in subcutaneous and fibromuscular tissues.- ameloblastic s. SYN: ameloblastic fibrosarcoma.- botryoid s. a polypoid form of embryonal rhabdomyosarcoma that occurs in children, most frequently in the urogenital tract, characterized by the formation of grossly apparent grapelike clusters of neoplastic tissue that consist of rhabdomyoblasts and spindle and stellate cells in a myxomatous stroma; neoplasms of this type grow relatively rapidly and are highly malignant.- endometrial stromal s. a term sometimes used for a relatively rare s. believed to be a form of endometriosis in which the lesions form multiple foci in the myometrium and in vascular spaces in other sites, and which consist of histologic and cytologic elements that resemble those of the endometrial stroma.- granulocytic s. a malignant tumor of immature myeloid cells, frequently subperiosteal, associated with or preceding granulocytic leukemia. SEE ALSO: chloroma. SYN: myeloid s..- immunoblastic s. obsolete term for immunoblastic lymphoma.- juxtacortical osteogenic s. a form of osteogenic s. of relatively low malignancy, probably arising from the periosteum and initially involving cortical bone and adjacent connective tissue, which occurs in middle-aged as well as young adults and most commonly affects the lower part of the femoral shaft. SYN: periosteal s..- Kaposi s. a multifocal malignant neoplasm of primitive vasoformative tissue, occurring in the skin and sometimes in lymph node s or viscera, consisting of spindle cells and irregular small vascular spaces frequently infiltrated by hemosiderin-pigmented macrophages and extravasated red cells; clinically manifested by cutaneous lesions consisting of reddish-purple to dark-blue macules, plaques, or nodules; seen most commonly in men over 60 years of age and, in AIDS patients, as an opportunistic disease associated with human herpes virus 8 infection. SYN: multiple idiopathic hemorrhagic s..- myeloid s. SYN: granulocytic s..- osteogenic s. the most common and malignant of bone sarcomas, which arises from bone-forming cells and affects chiefly the ends of long bones; its greatest incidence is in the age group between 10 and 25 years. SYN: osteosarcoma.- periosteal s. SYN: juxtacortical osteogenic s..- round cell s. obsolete term for an undifferentiated malignant neoplasm, believed to be of mesenchymal origin, composed chiefly of closely packed round cells.- Rous s. a fibrosarcoma, originally observed in a Plymouth Rock hen, now thought to be an expression of infection by certain viruses of the avian leukosis-s. complex in the family Retroviridae. SYN: avian s., Rous tumor.- spindle cell s. a malignant neoplasm of mesenchymal origin composed of elongated, spindle-shaped cells. SYN: fascicular s..- synovial s. a rare malignant tumor of synovial origin, most commonly involving the knee joint and composed of spindle cells usually enclosing slits or pseudoglandular spaces that may be lined by radially disposed epithelial-like cells.- telangiectatic osteogenic s. a lytic cystic variant of osteogenic s. composed of aneurysmal blood-filled spaces lined by s. cells producing osteoid.
* * *sar·co·ma sär-'kō-mə n, pl -mas also -ma·ta -mət-ə a malignant tumor arising in tissue of mesodermal origin (as connective tissue, bone, cartilage, or striated muscle) that spreads by extension into neighboring tissue or by way of the bloodstream compare CARCINOMA
* * *n.any cancer of connective tissue. These tumours may occur in any part of the body, as they arise in the tissues that make up an organ rather than being restricted to a particular organ. They can arise in fibrous tissue, muscle, fat, bone, cartilage, synovium, blood and lymphatic vessels, and various other tissues. See also chondrosarcoma, fibrosarcoma, leiomyosarcoma, liposarcoma, lymphangiosarcoma, osteosarcoma, rhabdomyosarcoma.• sarcomatous adj.
* * *sar·co·ma (sahr-koґmə) pl. sarcomas, sarcoґmata [sarc- + -oma] any of a group of tumors usually arising from connective tissue, although the term now includes some of epithelial origin; most are malignant. Many types have prefixes denoting the type of tissue or structure involved; see chondrosarcoma, fibrosarcoma, lymphosarcoma, myxosarcoma, osteosarcoma, rhabdomyosarcoma, and so on. sarcomatous adj
Medical dictionary. 2011.