tumor

tumor:

see neoplasmneoplasm
or tumor,
tissue composed of cells that grow in an abnormal way. Normal tissue is growth-limited, i.e., cell reproduction is equal to cell death. Feedback controls limit cell division after a certain number of cells have developed, allowing for tissue repair
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Tumor

(also neoplasm), the excessive, pathological growth of plant, animal, or human tissues in which the cells qualitatively change and lose their capacity for differentiation. Tumor cells transmit their pathological properties to their offspring and continue to multiply even after the causative factors cease to act. In contrast to pseudotumors, which result from injury, inflammation, or circulatory disturbance, true tumors enlarge as a result of multiplication of their own cells. True tumors include leu-kemias. Oncology, which is the study of tumors, has devoted most attention to tumors in man, mice, rats, hamsters, and dogs.

For purposes of clinical and morphological description, a distinction is made between benign and malignant tumors. Benign tumors enlarge to distend and sometimes also compress the surrounding tissues, whereas malignant tumors invade and destroy the surrounding tissues while injuring the blood and lymphatic vessels. Tumor cells can be carried throughout the body in the bloodstream or in the lymph and can settle in various organs and tissues, forming metastases. Benign tumors do not metastasize, but they may be dangerous because of their location, for example, they can compress vital tissues when they develop in the brain. The occurrence, rate, and degree of metastasis depend on the immunobiological state of the organism.

The first sign of tumor growth in a tissue is the appearance of a small number of cells that exhibit a tendency toward uncontrolled division. Tumor growth proceeds through stages of irregular hyperplasia, or a disorderly increase in the number of cells, focal growth, benign growth, and malignant growth; the stages immediately preceding malignancy—focal and benign growth—are called precancerous. The evidence of many clinical observations and animal experiments confirms that every cancer develops through a precancerous stage. Tumor development is progressive, that is, it proceeds through stages of increasing malignancy. The autonomy of the tumor increases in that the tumor becomes more independent of the bodily systems that normally control cell division.

The parenchyma of a tumor consists of tumorous tissue, while the stroma forms from surrounding connective tissue. A tumor is named by adding the Greek suffix -oma to the name of the tissue from which it originated. For example, a tumor from cartilage is a chondroma and a tumor from muscle a myoma. Some tumors have special names. For instance, a malignant tumor from connective tissue is called a sarcoma (from Greek sarx, gen. case sarkos, “meat”) because in cross section its tissue resembles fish meat. A malignant epithelioma is called a carcinoma (from Greek karkinos, “cancer”). In many countries the word “cancer” is applied to all malignant tumors regardless of the source. Soviet oncologists use “cancer” to refer only to malignant tumors of epithelial origin. Some tumors are named after the organ or organ part from which they originate; for example, an insuloma is a tumor from the islands of Langerhans, in the pancreas.

Experimental studies played a major role in elucidating the nature and causes of tumors. The autonomous growth of tumors was demonstrated by transplantation experiments in which tumors from one animal survived and grew for many years on secondary animal hosts. Tumor strains, consisting of tumors that are repeatedly transplanted over a long period of time, are used to study the properties of tumors and to develop and test methods of treating tumors, especially chemotherapeutic methods. Modern experimental oncology also makes use of explanation studies, in which tumorous tissues and cells are excised for cultivation outside the organism. Experimental studies showed that many tumors can be caused by viruses. However, cancer and most other tumors are not considered infectious in the ordinary sense of the word.

Evidence shows that individuals who work at jobs that involve prolonged contact with certain substances may develop cancer; for example, chimney sweeps are prone to skin cancer, and uranium miners tend to develop cancer of the lungs. These observations led to experiments that showed that several substances belonging to different classes of chemical compounds may cause cancer and other tumors. These substances are called carcinogens. Tumors can be caused not only by exogenous substances, that is, by those that appear in the environment, but also by endogenous carcinogens, which originate in the organism itself. Endogenous carcinogens can form, for example, as a result of disturbances of protein metabolism in which derivatives of the amino acid tryptophan or tyrosine are present and as a result of disturbances in steroid metabolism, especially disturbances in the metabolism of steroid sex hormones. Many human tumors have a dyshormonal origin, including those of the breast, prostate, uterine body, uterine muscles, and, occasionally, ovaries and testicles. In addition to being caused by viruses and chemicals, tumors can be caused by radiation. Thus, tumors may result from a variety of physical, chemical, and biological factors. The internal mechanisms by which these factors operate have not been fully explained.

The systemic reaction of the body strongly influences the origin and development of tumors. This reaction depends on both genotype and environmental factors. Some rare forms of tumors and precancerous states are definitely inheritable in man, for example, retinoblastoma and xeroderma pigmentosum. The latter readily becomes malignant after exposure to ultraviolet radiation. However, hereditary transmission of most tumors has not been demonstrated. Hereditary factors mainly predispose an organism to tumor growth, by altering the body’s response to tumorigenic influences. The general condition of the body, which is dependent on such factors as nutrition, plays a decisive role in the realization of the specific effect of these influences.

Tumors are clinically diagnosed by instrumental methods, including roentgenography and endoscopy, and by morphological, immunological, and chemical methods. Early diagnosis is essential because treatment is most effective in the early stages of the disease. A conclusive diagnosis is often based on biopsy results.

Tumors are treated with surgery, radiation therapy, and chemotherapy, and combinations of these methods. The location, structure, and stage of development of the tumors are taken into account when selecting a method. Surgery is the most important method in the treatment of tumors of the alimentary canal; radiation is used against tumors of the lower lip, skin, and uterine cervix; a combination of surgery, radiation, and chemotherapy is used with breast cancer. Chemotherapy, the newest approach, is effective as an independent method in, for example, chorionepithelioma, or choriocarcinoma, a malignant tumor of the uterine body in young women.

Epidemiological studies are of value in oncology and tumor prevention. Statistics on cancer morbidity and mortality rates are gathered in many countries. In the USSR, patients with malignant tumors must be registered. This information is very helpful in studying the prevalence of tumors in different parts of the country and in detecting possible etiological relationships between a particular oncological disease and natural or ethnographic factors.

Malignant tumors are the second leading cause of death in the economically developed countries, including the USSR, the USA, Great Britain, France, and Sweden. In descending order of frequency of occurrence, the most common cancers in the majority of countries are those of the lung, uterus, female breast, and male esophagus. Malignant tumors mostly affect older persons. An increase in the average life expectancy and improved methods of diagnosis may explain the apparent increase in tumor morbidity and mortality that has been observed. Special correction factors in the form of standardized indexes are used in the statistical analysis of oncological data. Worldwide statistics revealed significant unevenness in the distribution of the various types of tumors among different nations, different peoples, and different isolated populations. Skin cancer, especially on exposed parts of the body, was found to occur most frequently in hot countries, as a result of excessive Ultraviolet radiation. Cancer of the mouth, tongue, and gums is prevalent among Indians, Pakistanis, and inhabitants of some other Asian countries as a result of these people’s harmful habit of chewing betel. Penile cancer is common in some Asian and South American countries, probably because of careless personal hygiene.

Epidemiological studies have shown that the incidence of cancer in a particular geographical location changes when the living conditions of the people change. For example, among Englishmen who migrate to Australia, the USA, or South Africa, lung cancer is more common than among the indigenous populations of these countries but less common than in the general population of Great Britain itself. Stomach cancer is more widespread in Japan than in the United States. The Japanese who permanently reside in the United States, for example, in San Francisco, are more prone to stomach cancer than other American citizens but are less prone to stomach cancer and at a later age than their fellow countrymen in Japan.

Tumors can either be prevented from occurring (hygienic prevention) or from developing (clinical prevention). To prevent the occurrence of tumors, environmental conditions can be improved by completely or partially eliminating the carcinogens that constitute a potential threat to man. It has been well established that cancer develops more slowly and less frequently in environments that contain smaller amounts of carcinogen.

Early diagnosis and healing of precancers is essential in curtailing tumor development. The principal method of clinical prevention is systematic mass screening of the entire population and clinical observation of individual groups. Special methods are employed to prevent certain tumors. For example, regular cytological examination of vaginal smears permits prompt detection of cancer of the uterine cervix, and careful self-examination is an effective means of preventing breast cancer.

REFERENCES

Uspekhi v izuchenii raka, vols. 1–10. Edited by L. M. Shabad. Moscow, 1955–71. (Translated from English.)
Rukovodstvo po obshchei onkologii. Edited by N. N. Petrov. Leningrad, 1961.
Zil’ber, L. A. Virusogeneticheskaia teoriia vozniknoveniia opukholei. Moscow, 1968.
Shabad, L. M. Endogennye blastomogennye veshchestva. Moscow, 1969.
Shabad, L. M. O tsirkuliatsii kantserogenov v okruzhaiushchei srede. Moscow, 1973.
Klinicheskaia onkologiia, vols. 1–2. Edited by N. N. Blokhin and B. E. Peterson. Moscow, 1971.

L. M. SHABAD

In animals. Tumors are commonly found in all species. Their frequency increases with age and is under the influence of such parameters as species, breed, and climate. Tumors are especially common in dogs and chickens. Similar tumors in different animals are morphologically and clinically identical, but the frequency with which individual organs are affected varies. For example, mammary tumors are extremely rare in cows but are quite common in dogs, accounting for 35–40 percent of all canine tumors. Pulmonary fibromatosis frequently arises in sheep, and tumors of the eye are frequent in cattle. Stomach cancer is exceptionally rare in animals. Animal tumors are diagnosed by clinical examination, which includes cytological and roentgenological studies. The principal method of treatment is surgery, which is sometimes combined with chemotherapy and the administration of hormones.

P. F. TEREKHOV

In plants. Plant tumors may be caused by fungi, bacteria, viruses, insects, nematodes, or low temperature. They are biologically distinct from animal tumors and arise as a result of hyperplasia (intensified division) or hypertrophy (intensified growth) of plant cells. Plant tumors generally appear on roots, tubers, stems, and, less commonly, leaves. Typical examples are root canker of fruit trees, potato canker, and beet tuberculosis. Tumors impede the flow of nutrient solutions, especially when the main root or root collar is affected. Diseased plants often die prematurely. Control measures are aimed at eliminating the underlying causes of the tumors.

tumor

[′tü·mər] (medicine) Any abnormal mass of cells resulting from excessive cellular multiplication.

tumour

(US), tumor Pathola. any abnormal swelling b. a mass of tissue formed by a new growth of cells, normally independent of the surrounding structures

tumor

[too´mor] 1. swelling or morbid enlargement; this is one of the cardinal signs of inflammation.2. a new growth of tissue in which cell multiplication is uncontrolled and progressive. Tumors are also called 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 physiologic purpose. adj., adj tu´morous.
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 are found in glandular tissue and such organs as the breast, stomach, uterus, or skin; they also may be either benign or malignant (carcinoma). Mixed tumors contain different types of cells derived from the same primary germ layer, and teratomas" >teratomas contain cells derived from more than one germ layer; both kinds may be benign or malignant.Benign Tumors. Benign tumors do not endanger life unless they interfere with normal functions of other organs or affect a vital organ. They grow 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.Malignant Tumors. These tumors are 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.)

Gross appearance of benign (A) and malignant (B) tumors. From Damjanov, 2000.benign tumor one that lacks the properties of invasiveness and metastasis and that is usually surrounded by a fibrous capsule; its cells also show a lesser degree of anaplasia than those of a tumor" >malignant tumor do. bladder tumor a tumor of the urinary bladder; see also bladder cancer.brain tumor see brain tumor" >brain tumor.brown tumor a giant-cell granuloma produced in and replacing bone, occurring in osteitis fibrosa cystica and due to hyperparathyroidism.Burkitt's tumor Burkitt's lymphoma.Buschke-Löwenstein tumor a slow-growing mass of warts found usually in the prepuce but sometimes elsewhere in the perianal region; it starts as a plaque and may grow into a large cauliflowerlike mass. Called also giant condyloma.carcinoid tumor carcinoid (def. 1).carotid body tumor a chemodectoma of a carotid body, found as a firm round mass at the bifurcation of the common carotid artery.connective tissue tumor any tumor arising from a connective tissue structure, such as a fibroma or sarcoma.desmoid tumor desmoid" >desmoid (def. 1).endodermal sinus tumor yolk sac tumor.erectile tumor cavernous hemangioma.Ewing's tumor Ewing's sarcoma.false tumor pseudotumor.fibroid tumor 1. fibroma.2. leiomyoma uteri.germ cell tumor any of a group of tumors arising from primitive germ cells, usually of the testis or ovum; they range from benign to highly malignant. Types include germinoma, tumor" >yolk sac tumor, teratoma, carcinoma" >embryonal carcinoma, and some types of choriocarcinoma; many tumors are mixtures of types.giant cell tumor 1. a benign or malignant tumor containing giant cells; see under carcinoma, granuloma, and sarcoma.2. a bone tumor, ranging from benign to frankly malignant, composed of cellular spindle cell stroma containing multinucleated giant cells resembling osteoclasts.3. a small yellow benign tumorlike nodule of tendon sheath origin, usually of the wrist and fingers or ankle and toes, laden with lipophages and containing multinucleated giant cells.glomus tumor 1. a blue-red, extremely painful chemodectoma involving an arteriovenous anastomosis or cluster of blood cells, which may be found anywhere in the skin, most often in the distal portion of the fingers and toes, especially beneath the nail. Such tumors may also occur in the stomach and nasal cavity.2. chemodectoma.granular cell tumor a relatively common neoplasm whose cells have a granular appearance by light microscopy; it is usually benign but occasionally malignant, and multiple tumors may occur. It can be found anywhere but is most often seen in the oral cavity, especially in the tongue.granulosa tumor (granulosa cell tumor) see granulosa cell tumor.granulosa-theca cell tumor see granulosa-theca cell tumor.heterologous 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 see hürthle cell tumor.islet cell tumor a tumor of the islands of Langerhans; many secrete excessive amounts of hormones. Types include gastrinoma, glucagonoma, insulinoma, somatostatinoma, and vipoma.Krukenberg's tumor see krukenberg's tumor.lipoid cell tumor of ovary a usually benign ovarian tumor composed of eosinophilic cells or cells with lipoid vacuoles; it causes masculinization" >masculinization.tumor lysis syndrome severe hyperphosphatemia, hyperkalemia, hyperuricemia, and hypocalcemia occurring after effective induction chemotherapy of rapidly growing malignant neoplasms; thought to be due to release of intracellular products after cell lysis.malignant tumor one that has the properties of invasiveness and metastasis and that shows a greater degree of anaplasia than a tumor" >benign tumor does.mast cell tumor mastocytoma.melanotic neuroectodermal tumor a benign, rapidly growing, dark tumor of the jaw or occasionally some other site, almost always seen in infants; called also melanoameloblastoma.mixed tumor one composed of more than one type of neoplastic tissue.tumor necrosis factor receptor–associated periodic syndrome (TRAPS) familial periodic fever.organoid tumor teratoma.peripheral neuroectodermal tumor (PNET) any of a heterogeneous group of neoplasms originating in supporting structures or neuronal tissue, primarily of the extremities, pelvis, or chest wall; seen most often in adolescents and young adults and frequently having widespread metastases.plasma cell tumor 1. plasma cell dyscrasias.2. solitary myeloma.sand tumor psammoma.Sertoli-Leydig cell tumor androblastoma (def. 1).theca cell tumor a fibroidlike tumor of the ovary containing yellow areas of fatty material derived from theca cells.turban t's multiple cylindromas of the scalp that are grouped together so as to cover the entire scalp.Wilms' tumor a rapidly developing malignant mixed tumor of the kidneys, made up of embryonal elements, occurring chiefly in children before the seventh year; a genetic component is suspected in its etiology. It may be accompanied by congenital defects such as urinary tract abnormalities, absent iris of the eye, and asymmetry of parts. With treatment, the prognosis is excellent. Called also embryonal carcinosarcoma and nephroblastoma.yolk sac tumor a malignant tumor" >germ cell tumor of children that represents a proliferation of both yolk sac endoderm and extraembryonic mesenchyme. It produces α-fetoprotein and most often occurs in the testes, but is also seen in the ovaries and some extragonadal sites. Called also endodermal sinus tumor.

tu·mor

(tū'mŏr), Avoid the jargonistic use of this word as a synonym of neoplasm.1. Any swelling or tumefaction. 2. Synonym(s): neoplasm3. One of the four signs of inflammation (t., calor, dolor, rubor) enunciated by Celsus. [L. tumor, a swelling]

tumor

(to͞o′mər, tyo͞o′-)n.1. An abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function; a neoplasm.2. A swollen part; a swelling: a plant tumor.

tu′mor·al, tu′mor·ous adj.

tumor

1. A neoplasm, benign or malignant. See Benign tumor, Blue cell tumor, Bone tumor, Borderline tumor, Brain tumor, Carcinoid tumor, Carcinoma ex-mixed tumor, Carotid body tumor, Desmoid tumor, Desmoplastic round cell tumor, Ewing family of tumors, Fibrous tumor of childhood, Gastrointestinal autonomic nerve tumor, Gastrointestinal stromal tumor, Giant cell tumor of tendon sheath, Glial tumor, Glomus tumor, Granular cell tumor, Heart tumor, Hilus tumor, Hürthle cell tumor, Internists' tumor, Intracranial tumor, Krükenberg tumor, Kulchitsky cell tumor, Leydig cell tumor, Malignant mesodermal tumor, Medullary tumor, Metastatic tumor, Metastatic brain tumor, Mixed tumor, Neuroectodermal tumor, Neuroendocrine tumor, Pancreatic endocrine tumor, Peripheral nerve sheath tumor, Phantom tumor, Pigmented neuroectodermal tumor of infancy, Potato tumor, Pott's puffy tumor, Primary tumor, Pseudotumor, Pseudotumor cerebri, Round cell tumor, Sclerosing stromal tumor, Secondary tumor, Sex cord-stromal tumor, Skin adnexal tumor, Small round cell tumor, Solid tumor, Solid tumor of childhood, Spaghetti tumor, Spontaneous tumor, Steroid cell tumor, Sugar tumor, Theca cell tumor, Triton tumor, Turban tumor, Warthin's tumor, Wilms tumor, Yolk sac tumor.2. A term of waning popularity for a local swelling.

tu·mor

(tū'mŏr) 1. Any swelling or tumefaction. 2. Synonym(s): neoplasm, tumour. 3. One of the four signs of inflammation (tumor, calor, dolor, rubor) enunciated by Celsus.
Synonym(s): tumour. [L. tumor, a swelling]

tumor

(too'mor) [L. tumor, a swelling] 1. A swelling or enlargement; one of the four classic signs of inflammation.2. An abnormal mass. Growth or proliferation that is independent of neighboring tissues is a hallmark of all tumors, benign and malignant. Synonym: neoplasm See: cancer

adenomatoid odontogenic tumor

Adenoameloblastoma.

BRAIN TUMOR

brain tumor

An inexact term to describe any intracranial mass: neoplastic, cystic, inflammatory (abscess), or syphilitic.

Neoplastic brain tumors may be benign or malignant. Malignant brain lesions may be primary or secondary, resulting from metastatic spread of other cancers. Primary malignant brain tumors make up from 10% to 30% of adult cancers and about 20% in children, but any of these tumors may occur at any age. Incidence in children is usually greatest before age 12, with astrocytomas, medulloblastomas, ependymomas, and brain stem gliomas being most common. In adults the most common tumors are gliomas and meningiomas, usually occurring supratentorially. Other malignant tumor types are oligodendrogliomas and acoustic neuromas (Schwannomas). Most malignant brain tumors are metastatic, with 20% to 40% of patients with cancer developing brain metastasis. The cause of primary brain cancers is unknown; however, one known environmental risk is exposure to ionizing radiation. Cell phone use has been implicated in acoustic neuromas. Central nervous system changes occur as the lesions invade and destroy tissue, and, because the tumors compress the brain, cranial nerves, and cerebral blood vessels, the compression causes cerebral edema and increased intracranial pressure (ICP). Most clinical signs are due to the increased ICP, but signs and symptoms may vary due to the type of tumor, its location, and the degree and speed of invasion. Usually the onset of symptoms is insidious, with brain tumors frequently misdiagnosed.

Diagnosis

The patient is evaluated for neurological deficits (headache, mental activity changes, behavioral changes, weakness, sensory losses, or disturbances of vision, speech, gait, or balance). The patient is monitored for seizures and increased ICP. Diagnostic tools include skull x-rays, brain scan, CT scan, MRI, cerebral angiography, and EEG. Lumbar puncture demonstrates increased pressure and protein levels, decreased glucose levels, and (sometimes) tumor cells in the cerebrospinal fluid (CSF). Definitive diagnosis is by tissue biopsy performed by stereotactic surgery.

Treatment

Treatment includes excision if the tumor is resectable, and size reduction if he tumor is not respectable; relieving cerebral edema, reducing ICP, and managing other symptoms; and preventing further neurologic damage. Treatment is determined by the tumor’s histology, radiosensitivity, and location. Functional MRI can map the brain function surrounding a tumor to help design a surgical approach that removes the tumor while avoiding damage to areas critical for normal functioning. Surgery, radiation, chemotherapy, and/or decompression for increased ICP with diuretics, corticosteroids, or sometimes ventroatrial or ventroperitoneal CSF shunting. Focused and computerized robotic radiation methods such as the Gamma Knife and Cyberknife permit delivery of more radiation to the tumor and less to surrounding normal tissue.

Patient care

Radiation therapy can cause inflammation; therefore the patient is monitored for increasing ICP. If radiation is to be used after surgery, it will be delayed until the surgical wound has healed. However, even after local healing occurs, radiation can break down the wound; therefore the area of the incision must be assessed for infection and sinus formation. Chemotherapy for malignant brain tumors includes use of nitrosureas (BCNU, CCNU, procarbazine) to help break down the blood-brain barrier allowing entrance of other chemotherapy agents. Antiemetics are provided before and after chemotherapy to minimize nausea and prevent vomiting. The patient is assessed over the following weeks for bone marrow suppression, is advised to report signs of infection or bleeding, and is to avoid contact with crowds and people with respiratory infections. The oral agent temozolomide (Temodar) crosses the blood-brain barrier and is usually well tolerated by the patient. Intrathecal or intra-arterial administration helps increase drug action. Convection-enhanced delivery systems infuse the antitumor agent directly into the brain, bypassing the blood-brain barrier, to pump drugs slowly through 2 to 4 implanted catheters to where a tumor was removed, to attach to and kill remaining tumor cells, and to shrink a tumor before surgery. A disc-shaped drug wafer can be implanted during surgery to deliver chemotherapy directly to the tumor. MRI spectroscopy reveals the physiology of treated tumors to differentiate dead tissue from an actively growing tumor. The patient must be monitored closely for changes in neurologic status and increases in ICP. A patent airway must be maintained and respiratory changes monitored. The patient's safety must be ensured. Temperature must be monitored closely. Steroids and osmotic diuretics are administered as prescribed. Fluid intake may be restricted to 1500 ml/24 hr. Fluid and electrolyte balance is monitored to prevent dehydration. Stress ulcers may occur; therefore the patient is assessed for abdominal distention, pain, vomiting, and tarry stools. Stools are tested for occult blood. Antacids and anti-histamine-2 agents are administered as prescribed.

For postcraniotomy surgery, all general patient care concerns apply. General neurologic status and ICP remain the assessment priorities. Positioning of the patient after surgery depends on the procedure: after supratentorial craniotomy, the head of the bed should be elevated 30° and the patient positioned on the side to promote venous drainage, reduce cerebral edema, allow drainage of secretions and prevent aspiration. After infratentorial craniotomy, the patient should be kept flat for 48 hr but log-rolled side to side every 2 hr to minimize complications from immobility. Because brain tumors and their treatment frequently result in residual disabling neurologic deficits, a rehabilitation program should be started early. Physical and occupational therapists help the patient maintain independence and quality of life and provide aids for self-care and mobility. If the patient is aphasic or develops dysphagia, a speech pathologist must be consulted. Depression is common, and psychological consultation for behavioral or drug therapies may be helpful.

Emotional support is provided to the patient and family for treatments, disabilities, changes in lifestyle, and end-of-life issues. The patient and family are referred to resource and support services (e.g., social service, home health care agencies, the American Cancer Society, and other such voluntary agencies).

illustration

Brenner tumor

See: Brenner tumor

brown tumor

A benign fibrotic mass found within the bone of patients with unchecked hyperparathyroidism. The tumor appears brown on gross examination because it contains blood and by-products of the metabolism of hemoglobin.

Buschke-Loewenstein tumor

A giant condyloma acuminatum, typically found on the genitals or anus, caused by infection with papilloma virus. In men, it is almost always found under the foreskin (it is rarely reported in circumcised men). It may transform into a verrucous carcinoma and cause deep local tissue invasion.

calcifying epithelial odontogenic tumor

Pindborg tumor.

carotid body tumor

A benign tumor of the carotid body.

collision tumor

1. A malignant growth made up of two or more different cell types occurring simultaneously in the same location.2. A cancerous growth made up of two or more malignancies that have metastasized toward each other.

connective tissue tumor

Any tumor of connective tissue such as fibroma, lipoma, chondroma, or sarcoma.

Dapaong tumor

A painful, nodular mass in the large bowel, a result of infection with Oesophagostomum bifurcum, a West African worm.

desmoid tumor

A tumor of fibrous connective tissue. Synonym: desmoma

dysembryoplastic neuroepithelial tumor

Abbreviation: DNET
A benign mass of misshapen brain cells. DNETs are a relatively rare cause of seizures in children and adolescents.

endocrine-inactive tumor

A pituitary adenoma that does not secrete a clinically important concentration of hormones. Endocrine-inactive tumors were formerly known as chromophobe adenomas. They are the most commonly detected neoplasms of the pituitary gland.

erectile tumor

A tumor composed of erectile tissue.

Ewing tumor

See: Ewing tumor

false tumor

An enlargement due to hemorrhage into tissue or extravasation of fluid into a space, rather than cancer.

fibroid tumor

Uterine leiomyoma.

follicular tumor

An epidermoid cyst.

functioning tumor

A tumor that is able to synthesize the same product as the normal tissues from which it arises, esp. an endocrine or nonendocrine tumor that produces hormones.

giant cell tumor

1. A malignant or benign bone tumor that probably arises from connective tissue of the bone marrow. Histologically, it contains a vascular reticulum of stromal cells and multinucleated giant cells. 2. A yellow giant cell tumor of a tendon sheath.3. Epulis.4. A chondroblastoma.

giant cell tumor of bone

A benign or malignant tumor of bone in which the cells are multinucleated and surrounded by cellular spindle cell stroma.

giant cell tumor of tendon sheath

A localized nodular tenosynovitis.

granulosa cell tumor

A malignant tumor that arises from the supporting cells (stromal cells) that encircle the ovary. Many of these cells produce estrogen; those that do can cause breast tenderness, endometrial hyperplasia, menorrhagia, or, in children, sexual precocity.

granulosa-theca cell tumor

An estrogen-secreting tumor of the ovary made up of either granulosa or theca cells.

Gubler tumor

See: Gubler, Adolphe

heterologous tumor

A tumor in which the tissue differs from that in which it is growing.

homologous tumor

A tumor in which the tissue resembles that in which it is growing.

Hürthle cell tumor

See: Hürthle, Karl W.

hilus cell tumor

A rare, steroid-hormone–producing tumor of the ovary. It is an occasional cause of virilization.

islet cell tumor

A tumor of the islets of Langerhans of the pancreas.

Klatskin tumor

See: Klatskin tumor

Krukenberg tumor

See: Krukenberg, Friedrich Ernst

lipoid cell tumor of the ovary

A masculinizing tumor of the ovary. It may be malignant.

mast cell tumor

A benign nodular accumulation of mast cells.

melanotic neuroectodermal tumor

A benign tumor of the jaw, occurring mostly during the first year of life.

mesenchymal mixed tumor

A tumor composed of tissue that resembles mesenchymal cells.

milk tumor

A colloquial term for a galactocele. Synonym: galactocele (1) See: caked breast

Pancoast tumor

See: Pancoast tumor

papillary tumor

A neoplasm composed of or resembling enlarged papillae. See: papilloma

phantom tumor

1. An apparent tumor due to muscular contractions or flatus that resolves on reexamination of the patient.2. A mass that resembles a tumor in only one view of a chest x-ray film. On other views it either disappears or appears to be an encapsulated fluid collection.

placental site trophoblastic tumor

Abbreviation: PSTT
A rare form of gestational trophoblastic disease simulating carcinoma and arising at the attachment of the placenta to the uterine wall.

Pindborg tumor

See: Pindborg tumor

primary tumor

In a patient with metastatic cancer, the lesion assumed to be the source of the metastases.

primitive neuroectodermal tumor

Abbreviation: PNET
Medulloblastoma.

Recklinghausen tumor

See: Recklinghausen, Friedrich D. von

sand tumor

Psammoma.

secondary tumor

A tumor that has formed at a location remote from the original location of the tumor. Generally, a secondary tumor results from the spread of malignant cells through the lymphatic system or bloodstream.

teratoid tumor

A tumor of embryonic remains from all germinal layers. See: teratoma

turban tumor

Multiple cutaneous cylindromata that cover the scalp like a turban.

uterine tumor

, tumor of the uterusUterine neoplasia, which may cause sterility or abortion or obstruct labor. Uterine tumors may become infected or twisted on their attachments. See: cancer of uterus; endometrioma; uterine fibroma

vascular tumor

Hemangioma.

Warthin tumor

See: Warthin tumor

Wilms tumor

See: Wilms tumor

Tumor

An abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells.Mentioned in: Atelectasis, Choriocarcinoma, Laparoscopy, Mycetoma, Neurofibromatosis, Retinoblastoma

tu·mor

(tū'mŏr) Avoid the jargonistic use of this word as a synonym of neoplasm.1. Any swelling or tumefaction. 2. One of the four signs of inflammation (the others are, calor, dolor, rubor) enunciated by Celsus.
Synonym(s): tumour. [L. tumor, a swelling]

Patient discussion about tumor

Q. What is a brain tumor? A. A brain tumour is any intracranial tumor normally either in the brain itself in the cranial nerves, in the brain envelopes, skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). It is created by abnormal and uncontrolled cell division. Primary (true) brain tumors (which start in the brain) are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain.

Q. Is this a tumor? I felt a lump in my breast a few days ago in the shower. Is this a Tumor? Help! I'm scared.A. If you felt a lump in your breast then you should go see your Doctor to check whether or not it is something that could be dangerous.

Q. what is carcinoid tumors? I had my appendix removed and the doctor came in the room very shocked and said it was full of carcinoid tumors. Im scared to get them somewhere else.A. ya I have pain all the time but the doctors wont give me anything cuz im so young they don't want me hooked on anything. thank you sooo much for being so kind.

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REFERENCES

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tu·mor

tumor

tumor

tu·mor

tumor

adenomatoid odontogenic tumor

brain tumor

Diagnosis

Treatment

Patient care

Brenner tumor

brown tumor

Buschke-Loewenstein tumor

calcifying epithelial odontogenic tumor

carotid body tumor

collision tumor

connective tissue tumor

Dapaong tumor

desmoid tumor

dysembryoplastic neuroepithelial tumor

endocrine-inactive tumor

erectile tumor

Ewing tumor

false tumor

fibroid tumor

follicular tumor

functioning tumor

giant cell tumor

giant cell tumor of bone

giant cell tumor of tendon sheath

granulosa cell tumor

granulosa-theca cell tumor

Gubler tumor

heterologous tumor

homologous tumor

Hürthle cell tumor

hilus cell tumor

islet cell tumor

Klatskin tumor

Krukenberg tumor

lipoid cell tumor of the ovary

mast cell tumor

melanotic neuroectodermal tumor

mesenchymal mixed tumor

milk tumor

Pancoast tumor

papillary tumor

phantom tumor

placental site trophoblastic tumor

Pindborg tumor

primary tumor

primitive neuroectodermal tumor

Recklinghausen tumor

sand tumor

secondary tumor

teratoid tumor

turban tumor

uterine tumor

vascular tumor

Warthin tumor

Wilms tumor

Tumor

tu·mor

Patient discussion about tumor

tumor

tumor

Synonyms for tumor