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accumulation of fluid in the interlobar spaces of the lung, secondary to congestive heart failure, radiologically simulating a neoplasm.
a swelling resembling a tumor, usually caused by muscle contraction or gaseous distension of the intestines.
phan·tom tu·mor(fan'tŏm tū'mŏr)
1. Accumulation of fluid in the interlobar spaces of the lung, secondary to congestive heart failure, radiologically simulating a neoplasm.
2. A muscle contraction or gaseous distortion of the intestines.
1. swelling, one of the cardinal signs of inflammation; morbid enlargement.
2. neoplasm; a new growth of tissue in which cell multiplication is uncontrolled and progressive. A cancer.
Tumors are called also cancers or neoplasms, which means that they are composed of new and actively growing tissue. Their growth is faster than that of normal tissue, continuing after cessation of the stimuli that evoked the growth, and serving no useful physiological purpose.
Tumors are classified in a number of ways, one of the simplest being according to their origin and whether they are malignant or benign. Tumors of mesenchymal origin include fibroelastic tumors and those of bone, fat, blood vessels and lymphoid tissue. They may be benign or malignant (sarcoma). Tumors of epithelial origin may be benign or malignant (carcinoma); they are found in glandular tissue or such organs as the mammary gland, stomach, uterus or skin. Mixed tumors contain different types of cells derived from the same primary germ layer, and teratomas contain cells derived from more than one germ layer; both kinds may be benign or malignant.
ACTH secreting tumor
see corticotroph adenoma.
grows slowly, pushing aside normal tissue but not invading it. They are usually encapsulated, well-demarcated growths. They are not metastatic; that is, they do not form secondary tumors in other organs. Benign tumors usually respond favorably to surgical treatment and some forms of radiation therapy.
in cerebral arteriography, the pooling of contrast material where the blood-brain barrier has been interrupted.
a giant-cell granuloma produced in and replacing bone, occurring in osteitis fibrosa cystica and due to hyperparathyroidism.
see burkitt's lymphoma.
carotid body tumor
see carotid body tumors.
β cell tumor
tumor clinical staging
see staging (2).
connective tissue tumor
any tumor arising from a connective tissue structure, e.g. a fibroma or fibrosarcoma.
see desmoid (2).
see tumor enhancement.
structural enlargement due to extravasation, exudation, echinococcus or retained sebaceous matter.
giant cell tumor
see giant cell tumor.
granulosa tumor, granulosa cell tumor
a sex chord-stromal tumor, often referred to as granulosa-theca cell tumor, of the ovary originating in the cells of the cumulus oophorus. See also granulosa cell tumor.
granulosa-theca cell tumor
an ovarian tumor composed of granulosa (follicular) cells and theca cells; either form may predominate. See also granulosa-theca cell tumor.
one made up of tissue differing from that in which it grows.
homoiotypic tumor, homologous tumor
one made up of tissue resembling that in which it grows.
Hürthle cell tumor
a new growth of the thyroid gland composed wholly or predominantly of Hürthle cells. See also hürthle cell tumor.
see tumor-specific antigen.
islet cell tumor
a tumor of the islets of Langerhans, which may result in hyperinsulinism. See also insulinoma.
tumor lysis syndrome
a possible sequel to chemotherapy in which very rapid destruction of highly sensitive tumor cells results in release of large amounts of nucleic acid purines, lactate and uric acid which exceed renal and hepatic excretory mechanisms. Characterized by hyperkalemia, hyperphosphatemia, hypocalcemia, hyperuricemia and renal failure.
composed of embryonic, primitive, or poorly differentiated cells. They grow in a disorganized manner and so rapidly that nutrition of the cells becomes a problem. For this reason necrosis and ulceration are characteristic of malignant tumors. They also invade surrounding tissues and are metastatic, initiating the growth of similar tumors in distant organs. See also cancer.
mast cell tumor
a benign, but occasionally malignant, local aggregation of mast cells forming a nodulous tumor. Mast cell tumors with diffuse visceral involvement are called systemic mastocytosis. See also mast cell tumor.
one composed of more than one type of neoplastic tissue, as in mammary tumors.
tumor necrosis factor (TNF)
two related cytokines produced by macrophages (TNF-α) and some T cells (TNF-β) that are cytotoxic for tumor cells but not for normal cells and which exert a variety of other inflammatory effects. See also lymphotoxin.
tumor-node-metastases (TNM) classification
see TNM staging.
abdominal or other swelling not due to structural change.
tumor-specific antigen (TSA)
see tumor-specific antigen.