Ewing's sarcoma(redirected from peripheral primitive neuroectodermal tumour)
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sarcoma[sahr-ko´mah] (pl. sarcomas, sarco´mata.)
A tumor, often highly malignant, composed of cells derived from connective tissue such as bone, cartilage, muscle, blood vessel, or lymphoid tissue; sarcomas usually develop rapidly and metastasize through the lymph channels. Different types are named for the specific tissue they affect: fibrosarcoma in fibrous connective tissue; lymphosarcoma in lymphoid tissues; osteosarcoma in bone; chondrosarcoma in cartilage; rhabdosarcoma in muscle; and liposarcoma in fat cells. adj., adj sarco´matous.
Abernethy's sarcoma a malignant fatty tumor occurring mainly on the trunk.
alveolar soft part sarcoma one with a reticulated fibrous stroma enclosing groups of sarcoma cells enclosed in alveoli walled with connective tissue.
botryoid sarcoma (sarcoma botryoi´des) an embryonal rhabdomyosarcoma arising in submucosal tissue, usually in the upper vagina, cervix uteri, or bladder neck in young children and infants, presenting grossly as a polypoid grapelike structure.
endometrial stromal sarcoma a pale, polypoid, fleshy, malignant tumor of the endometrial stroma.
Ewing's sarcoma a malignant tumor of the bone that arises in medullary tissue, usually found in cylindrical bones, with pain, fever, and leukocytosis as prominent symptoms; called also Ewing's tumor.
giant cell sarcoma a malignant form of giant cell tumor of bone.
granulocytic sarcoma chloroma.
immunoblastic sarcoma of B cells an aggressive B-cell lymphoma believed to arise from transformed interfollicular B lymphocytes, which in many cases is associated with a preexisting immunologic disorder, e.g., Sjögren's syndrome, systemic lupus erythematosus, or Hashimoto's thyroiditis, or with an immunocompromised state.
immunoblastic sarcoma of T cells a group of T-cell lymphomas comprising tumors derived from T lymphocytes in the paracortical area arising from a mixture of small lymphocytes and many large transformed cells; the latter are characterized by one or more small but distinctly eosinophilic nucleoli.
Kaposi sarcoma a multicentric, malignant neoplastic vascular proliferation characterized by bluish red cutaneous nodules, usually on the lower extremities, most often on the toes or feet; the nodules slowly increase in size and number and spread to more proximal sites. Tumors often remain confined to skin and subcutaneous tissue, but widespread visceral involvement may occur. The condition occurs endemically in certain parts of Central Africa and Central and Eastern Europe, and a particularly virulent and disseminated form occurs in immunocompromised patients such as transplant recipients and those with acquired immunodeficiency syndrome. Human herpesvirus 8 has been implicated as a causative agent.
lymphatic sarcoma diffuse lymphoma.
osteogenic sarcoma a malignant primary tumor of bone composed of a malignant connective tissue stroma with evidence of osteoid, bone, and/or cartilage formation; depending upon the dominant component, classified as osteoblastic, fibroblastic, or chondroblastic.
pseudo–Kaposi sarcoma unilateral subacute to chronic dermatitis, often with postinflammatory hyperpigmentation, occurring in association with underlying arteriovenous fistula, which closely resembles Kaposi sarcoma both clinically and histologically.
reticulum cell sarcoma histiocytic lymphoma.
Etymology: James Ewing, American pathologist, 1866-1943
a malignant tumor that develops from bone marrow, usually in long bones or the pelvis. It occurs most frequently in adolescent boys and is characterized by pain, swelling, fever, and leukocytosis. The tumor, a soft, crumbly grayish mass that may invade surrounding soft tissues, may be difficult to distinguish histologically from a neuroblastoma or a lymphoma. Surgery, chemotherapy, and radiotherapy are often used in treatment. Also called endothelial myeloma, Ewing's tumor. See also neuroblastoma, histiocytic malignant lymphoma.
Ewing's sarcomaaggressive neoplasm of long bones of the leg and calcaneum in young people (middle to teenage years), characterized by unremitting pain, local soft-tissue swelling and pathological fracture; lesions present on radiograph as local bone destruction, with periosteal reaction and reactive sclerosis (especially with calcaneum involvement); differential diagnosis includes osteomyelitis
n.pr See sarcoma, Ewing's.