A benign tumor of fibrous or fully developed connective tissue.

A benign central bone tumor, usually of the jaws (especially the mandible), composed of fibrous connective tissue within which bone is formed.

A extremely rare bone tumor characterized by abundant collagen formation and a fibrous stroma, without evidence of mitosis or pleomorphism. It appears on x-rays as an osteolytic lesion with well-defined margins and must be differentiated from primary fibrosarcoma of bone. (DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1441)

Neoplasms produced from tooth-forming tissues.

Tumors or cancer of the MANDIBLE.

Cancers or tumors of the MAXILLA or MANDIBLE unspecified. For neoplasms of the maxilla, MAXILLARY NEOPLASMS is available and of the mandible, MANDIBULAR NEOPLASMS is available.

A disease of bone marked by thinning of the cortex by fibrous tissue containing bony spicules, producing pain, disability, and gradually increasing deformity. Only one bone may be involved (FIBROUS DYSPLASIA, MONOSTOTIC) or several (FIBROUS DYSPLASIA, POLYOSTOTIC).

A benign neoplasm derived from mesodermal cells that form cartilage. It may remain within the substance of a cartilage or bone (true chondroma or enchondroma) or may develop on the surface of a cartilage (ecchondroma or ecchondrosis). (Dorland, 27th ed; Stedman, 25th ed)

A benign tumor composed of fat cells (ADIPOCYTES). It can be surrounded by a thin layer of connective tissue (encapsulated), or diffuse without the capsule.

Cancer or tumors of the MAXILLA or upper jaw.

'Gingival neoplasms' are abnormal, uncontrolled growths of tissue originating from the gingiva, which can be benign (non-cancerous) or malignant (cancerous), often manifesting as swellings, ulcerations, or masses within the oral cavity.

A family of double-stranded DNA viruses infecting mammals (including humans), birds and insects. There are two subfamilies: CHORDOPOXVIRINAE, poxviruses of vertebrates, and ENTOMOPOXVIRINAE, poxviruses of insects.

An odontogenic fibroma in which cells have developed into cementoblasts and which consists largely of cementum.

Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.

A gonadal stromal neoplasm composed only of THECA CELLS, occurring mostly in the postmenopausal OVARY. It is filled with lipid-containing spindle cells and produces ESTROGENS that can lead to ENDOMETRIAL HYPERPLASIA; UTERINE HEMORRHAGE; or other malignancies in postmenopausal women and sexual precocity in girls. When tumors containing theca cells also contain FIBROBLASTS, they are identified as thecoma-fibroma tumors with less active hormone production.

A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). (From Dorland, 27th ed)

The total amount (cell number, weight, size or volume) of tumor cells or tissue in the body.

Tumors or cancer located in bone tissue or specific BONES.

A usually benign tumor composed of cells which arise from chondroblasts or their precursors and which tend to differentiate into cartilage cells. It occurs primarily in the epiphyses of adolescents. It is relatively rare and represents less than 2% of all primary bone tumors. The peak incidence is in the second decade of life; it is about twice as common in males as in females. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1846)

Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.

Tumors in any part of the heart. They include primary cardiac tumors and metastatic tumors to the heart. Their interference with normal cardiac functions can cause a wide variety of symptoms including HEART FAILURE; CARDIAC ARRHYTHMIAS; or EMBOLISM.

A benign tumor derived from striated muscle. It is extremely rare, generally occurring in the tongue, neck muscles, larynx, uvula, nasal cavity, axilla, vulva, and heart. These tumors are treated by simple excision. (Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1354)

Viruses that produce tumors.

A cell line derived from cultured tumor cells.

A benign tumor derived from smooth muscle tissue, also known as a fibroid tumor. They rarely occur outside of the UTERUS and the GASTROINTESTINAL TRACT but can occur in the SKIN and SUBCUTANEOUS TISSUE, probably arising from the smooth muscle of small blood vessels in these tissues.

A genus of the family POXVIRIDAE, subfamily CHORDOPOXVIRINAE, consisting of ether-sensitive viruses of leporids and squirrels. They commonly cause tumors and are usually transmitted mechanically by arthropods. MYXOMA VIRUS is the type species.

Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.

A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. (Stedman, 25th ed)

A neoplasm that arises from SCHWANN CELLS of the cranial, peripheral, and autonomic nerves. Clinically, these tumors may present as a cranial neuropathy, abdominal or soft tissue mass, intracranial lesion, or with spinal cord compression. Histologically, these tumors are encapsulated, highly vascular, and composed of a homogenous pattern of biphasic fusiform-shaped cells that may have a palisaded appearance. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp964-5)

Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.

A focal malformation resembling a neoplasm, composed of an overgrowth of mature cells and tissues that normally occur in the affected area.

A benign neoplasm derived from glandular epithelium, in which cystic accumulations of retained secretions are formed. In some instances, considerable portions of the neoplasm, or even the entire mass, may be cystic. (Stedman, 25th ed)

Genes that inhibit expression of the tumorigenic phenotype. They are normally involved in holding cellular growth in check. When tumor suppressor genes are inactivated or lost, a barrier to normal proliferation is removed and unregulated growth is possible.

Tumors or cancer of the SKIN.

Tumors or cancer of the PAROTID GLAND.

Tomography using x-ray transmission and a computer algorithm to reconstruct the image.

A malignant kidney tumor, caused by the uncontrolled multiplication of renal stem (blastemal), stromal (STROMAL CELLS), and epithelial (EPITHELIAL CELLS) elements. However, not all three are present in every case. Several genes or chromosomal areas have been associated with Wilms tumor which is usually found in childhood as a firm lump in a child's side or ABDOMEN.

Extraoral body-section radiography depicting an entire maxilla, or both maxilla and mandible, on a single film.

Tumors or cancer of the PALATE, including those of the hard palate, soft palate and UVULA.

Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.

Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.

Histochemical localization of immunoreactive substances using labeled antibodies as reagents.

Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.

A vascular anomaly due to proliferation of BLOOD VESSELS that forms a tumor-like mass. The common types involve CAPILLARIES and VEINS. It can occur anywhere in the body but is most frequently noticed in the SKIN and SUBCUTANEOUS TISSUE. (from Stedman, 27th ed, 2000)

Neoplasms of the bony part of the skull.

Neoplasms of whatever cell type or origin, occurring in the extraskeletal connective tissue framework of the body including the organs of locomotion and their various component structures, such as nerves, blood vessels, lymphatics, etc.

Tumors or cancer of the MAXILLARY SINUS. They represent the majority of paranasal neoplasms.

A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)

A usually small, slow-growing neoplasm composed of islands of rounded, oxyphilic, or spindle-shaped cells of medium size, with moderately small vesicular nuclei, and covered by intact mucosa with a yellow cut surface. The tumor can occur anywhere in the gastrointestinal tract (and in the lungs and other sites); approximately 90% arise in the appendix. It is now established that these tumors are of neuroendocrine origin and derive from a primitive stem cell. (From Stedman, 25th ed & Holland et al., Cancer Medicine, 3d ed, p1182)

Tumors or cancer of the PARANASAL SINUSES.

Autosomal dominant neurocutaneous syndrome classically characterized by MENTAL RETARDATION; EPILEPSY; and skin lesions (e.g., adenoma sebaceum and hypomelanotic macules). There is, however, considerable heterogeneity in the neurologic manifestations. It is also associated with cortical tuber and HAMARTOMAS formation throughout the body, especially the heart, kidneys, and eyes. Mutations in two loci TSC1 and TSC2 that encode hamartin and tuberin, respectively, are associated with the disease.

A benign neoplasm derived from connective tissue, consisting chiefly of polyhedral and stellate cells that are loosely embedded in a soft mucoid matrix, thereby resembling primitive mesenchymal tissue. It occurs frequently intramuscularly where it may be mistaken for a sarcoma. It appears also in the jaws and the skin. (From Stedman, 25th ed)

A benign tumor characterized histologically by tall columnar epithelium within a lymphoid tissue stroma. It is usually found in the salivary glands, especially the parotid.

The type species of LEPORIPOXVIRUS causing infectious myxomatosis, a severe generalized disease, in rabbits. Tumors are not always present.

The bonelike rigid connective tissue covering the root of a tooth from the cementoenamel junction to the apex and lining the apex of the root canal, also assisting in tooth support by serving as attachment structures for the periodontal ligament. (Jablonski, Dictionary of Dentistry, 1992)

A benign neoplasm composed of glandular and fibrous tissues, with a relatively large proportion of glands. (Stedman, 25th ed)

Tumors whose cells possess secretory granules and originate from the neuroectoderm, i.e., the cells of the ectoblast or epiblast that program the neuroendocrine system. Common properties across most neuroendocrine tumors include ectopic hormone production (often via APUD CELLS), the presence of tumor-associated antigens, and isozyme composition.

Neoplasms composed of connective tissue, including elastic, mucous, reticular, osseous, and cartilaginous tissue. The concept does not refer to neoplasms located in connective tissue.

Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.

A benign epithelial tumor with a glandular organization.

A benign neoplasm of muscular tissue. (Stedman, 25th ed)

A benign tumor containing vascular, adipose, and muscle elements. It occurs most often in the kidney with smooth muscle elements (angiolipoleiomyoma) in association with tuberous sclerosis. (Dorland, 27th ed)

A malignant epithelial tumor with a glandular organization.

Femoral neoplasms refer to abnormal growths or tumors, benign or malignant, located in the femur bone or its surrounding soft tissues within the thigh region.

A benign, slow-growing tumor, most commonly of the salivary gland, occurring as a small, painless, firm nodule, usually of the parotid gland, but also found in any major or accessory salivary gland anywhere in the oral cavity. It is most often seen in women in the fifth decade. Histologically, the tumor presents a variety of cells: cuboidal, columnar, and squamous cells, showing all forms of epithelial growth. (Dorland, 27th ed)

A pathologic process consisting of the proliferation of blood vessels in abnormal tissues or in abnormal positions.

Infections produced by oncogenic viruses. The infections caused by DNA viruses are less numerous but more diverse than those caused by the RNA oncogenic viruses.

The milieu surrounding neoplasms consisting of cells, vessels, soluble factors, and molecules, that can influence and be influenced by, the neoplasm's growth.

The transfer of a neoplasm from one organ or part of the body to another remote from the primary site.

Diseases of the domestic dog (Canis familiaris). This term does not include diseases of wild dogs, WOLVES; FOXES; and other Canidae for which the heading CARNIVORA is used.

Tumors or cancers of the KIDNEY.

Two or more abnormal growths of tissue occurring simultaneously and presumed to be of separate origin. The neoplasms may be histologically the same or different, and may be found in the same or different sites.

Tumors or cancer of the SALIVARY GLANDS.

Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.

Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.

Tumors of bone tissue or synovial or other soft tissue characterized by the presence of giant cells. The most common are giant cell tumor of tendon sheath and GIANT CELL TUMOR OF BONE.

A cystic tumor of the ovary, containing thin, clear, yellow serous fluid and varying amounts of solid tissue, with a malignant potential several times greater than that of mucinous cystadenoma (CYSTADENOMA, MUCINOUS). It can be unilocular, parvilocular, or multilocular. It is often bilateral and papillary. The cysts may vary greatly in size. (Dorland, 27th ed; from Hughes, Obstetric-Gynecologic Terminology, 1972)

Tumors or cancer of the UTERUS.

Tumors or cancer of the BRONCHI.

A cystic growth originating from lymphatic tissue. It is usually found in the neck, axilla, or groin.

Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.

Experimentally induced mammary neoplasms in animals to provide a model for studying human BREAST NEOPLASMS.

Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.

A blue-red, extremely painful vascular neoplasm involving a glomeriform arteriovenous anastomosis (glomus body), which may be found anywhere in the skin, most often in the distal portion of the fingers and toes, especially beneath the nail. It is composed of specialized pericytes (sometimes termed glomus cells), usually in single encapsulated nodular masses which may be several millimeters in diameter (From Stedman, 27th ed). CHEMODECTOMA, a tumor of NEURAL CREST origin, is also sometimes called a glomus tumor.

A scraping, usually of the interior of a cavity or tract, for removal of new growth or other abnormal tissue, or to obtain material for tissue diagnosis. It is performed with a curet (curette), a spoon-shaped instrument designed for that purpose. (From Stedman, 25th ed & Dorland, 27th ed)

A benign tumor resulting from a congenital malformation of the lymphatic system. Lymphangioendothelioma is a type of lymphangioma in which endothelial cells are the dominant component.

Tumors or cancer of the MAMMARY GLAND in animals (MAMMARY GLANDS, ANIMAL).

All of the processes involved in increasing CELL NUMBER including CELL DIVISION.

New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.

Carbohydrate antigen most commonly seen in tumors of the ovary and occasionally seen in breast, kidney, and gastrointestinal tract tumors and normal tissue. CA 125 is clearly tumor-associated but not tumor-specific.

Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.

A fibril-associated collagen found in many tissues bearing high tensile stress, such as TENDONS and LIGAMENTS. It is comprised of a trimer of three identical alpha1(XII) chains.

'Gingival diseases' is a general term for conditions affecting the soft tissues surrounding and supporting the teeth, primarily characterized by inflammation, bleeding, redness, or swelling, which can progress to periodontal disease if left untreated.

Tumors or cancer of the LIVER.

Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.

Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.

Spinal neoplasms are abnormal growths or tumors that develop within the spinal column, which can be benign or malignant, and originate from cells within the spinal structure or spread to the spine from other parts of the body (metastatic).

The local recurrence of a neoplasm following treatment. It arises from microscopic cells of the original neoplasm that have escaped therapeutic intervention and later become clinically visible at the original site.

Stable chromium atoms that have the same atomic number as the element chromium, but differ in atomic weight. Cr-50, 53, and 54 are stable chromium isotopes.

Unusual tumor affecting any site of the body, but most often encountered in the head and neck. Considerable debate has surrounded the histogenesis of this neoplasm; however, it is considered to be a myoblastoma of, usually, a benign nature. It affects women more often than men. When it develops beneath the epidermis or mucous membrane, it can lead to proliferation of the squamous cells and mimic squamous cell carcinoma.

Fibrous blood-filled cyst in the bone. Although benign it can be destructive causing deformity and fractures.

Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).

Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.

Tumors or cancer of the COLON.

The numerous (6-12) small thin-walled spaces or air cells in the ETHMOID BONE located between the eyes. These air cells form an ethmoidal labyrinth.

A type of connective tissue neoplasm typically arising from intralobular stroma of the breast. It is characterized by the rapid enlargement of an asymmetric firm mobile mass. Histologically, its leaf-like stromal clefts are lined by EPITHELIAL CELLS. Rare phyllodes tumor of the prostate is also known.

DNA present in neoplastic tissue.

Transplantation between animals of different species.

All tumors in the GASTROINTESTINAL TRACT arising from mesenchymal cells (MESODERM) except those of smooth muscle cells (LEIOMYOMA) or Schwann cells (SCHWANNOMA).

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

Tumors or cancer of the human BREAST.

A benign neoplasm composed of a mixture of adipose tissue and blood vessels. (Dorland, 27th ed)

The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.

A benign, painful, tumor of bone characterized by the formation of osteoid tissue, primitive bone and calcified tissue. It occurs frequently in the spine of young persons. (From Dorland, 27th ed; Stedman, 25th ed)

A mixed tumor of odontogenic origin, in which both the epithelial and mesenchymal cells exhibit complete differentiation, resulting in the formation of tooth structures. (Jablonski, Illustrated Dictionary of Dentistry, 1982)

Established cell cultures that have the potential to propagate indefinitely.

A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.

An immature epithelial tumor of the JAW originating from the epithelial rests of Malassez or from other epithelial remnants of the ENAMEL from the developmental period. It is a slowly growing tumor, usually benign, but displays a marked propensity for invasive growth.

In vivo methods of screening investigative anticancer drugs, biologic response modifiers or radiotherapies. Human tumor tissue or cells are transplanted into mice or rats followed by tumor treatment regimens. A variety of outcomes are monitored to assess antitumor effectiveness.

Neoplasms derived from the primitive sex cord or gonadal stromal cells of the embryonic GONADS. They are classified by their presumed histogenesis and differentiation. From the sex cord, there are SERTOLI CELL TUMOR and GRANULOSA CELL TUMOR; from the gonadal stroma, LEYDIG CELL TUMOR and THECOMA. These tumors may be identified in either the OVARY or the TESTIS.

Saccular lesions lined with epithelium and contained within pathologically formed cavities in the jaw; also nonepithelial cysts (pseudocysts) as they apply to the jaw, e.g., traumatic or solitary cyst, static bone cavity, and aneurysmal bone cyst. True jaw cysts are classified as odontogenic or nonodontogenic.

Inbred BALB/c mice are a strain of laboratory mice that have been selectively bred to be genetically identical to each other, making them useful for scientific research and experiments due to their consistent genetic background and predictable responses to various stimuli or treatments.

Multiple formation of chondromas. (Dorland, 27th ed)

A moderately firm, benign, encapsulated tumor resulting from proliferation of SCHWANN CELLS and FIBROBLASTS that includes portions of nerve fibers. The tumors usually develop along peripheral or cranial nerves and are a central feature of NEUROFIBROMATOSIS 1, where they may occur intracranially or involve spinal roots. Pathologic features include fusiform enlargement of the involved nerve. Microscopic examination reveals a disorganized and loose cellular pattern with elongated nuclei intermixed with fibrous strands. (From Adams et al., Principles of Neurology, 6th ed, p1016)

A usually benign glandular tumor composed of oxyphil cells, large cells with small irregular nuclei and dense acidophilic granules due to the presence of abundant MITOCHONDRIA. Oxyphil cells, also known as oncocytes, are found in oncocytomas of the kidney, salivary glands, and endocrine glands. In the thyroid gland, oxyphil cells are known as Hurthle cells and Askanazy cells.

An autosomal dominant inherited disorder (with a high frequency of spontaneous mutations) that features developmental changes in the nervous system, muscles, bones, and skin, most notably in tissue derived from the embryonic NEURAL CREST. Multiple hyperpigmented skin lesions and subcutaneous tumors are the hallmark of this disease. Peripheral and central nervous system neoplasms occur frequently, especially OPTIC NERVE GLIOMA and NEUROFIBROSARCOMA. NF1 is caused by mutations which inactivate the NF1 gene (GENES, NEUROFIBROMATOSIS 1) on chromosome 17q. The incidence of learning disabilities is also elevated in this condition. (From Adams et al., Principles of Neurology, 6th ed, pp1014-18) There is overlap of clinical features with NOONAN SYNDROME in a syndrome called neurofibromatosis-Noonan syndrome. Both the PTPN11 and NF1 gene products are involved in the SIGNAL TRANSDUCTION pathway of Ras (RAS PROTEINS).

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.

Neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors. Fibrillary astrocytomas are the most common type and may be classified in order of increasing malignancy (grades I through IV). In the first two decades of life, astrocytomas tend to originate in the cerebellar hemispheres; in adults, they most frequently arise in the cerebrum and frequently undergo malignant transformation. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2013-7; Holland et al., Cancer Medicine, 3d ed, p1082)

A tumor composed of cells resembling those of the hair matrix, which undergo 'mummification' and may calcify. It is a relatively uncommon tumor, which may occur at any age from infancy. The majority of patients are under 20, and females are affected more than males. The lesion is usually a solitary deep dermal or subcutaneous tumor 3-30 mm in diameter, situated in the head, neck, or upper extremity. (From Rook et al., Textbook of Dermatology, 4th ed, p2401)

The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the NASAL BONE and the CHEEK BONE on each side of the face.

Disappearance of a neoplasm or neoplastic state without the intervention of therapy.

An adenoma containing fibrous tissue. It should be differentiated from ADENOFIBROMA which is a tumor composed of connective tissue (fibroma) containing glandular (adeno-) structures. (From Dorland, 27th ed)

The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.

Tumors or cancer located in muscle tissue or specific muscles. They are differentiated from NEOPLASMS, MUSCLE TISSUE which are neoplasms composed of skeletal, cardiac, or smooth muscle tissue, such as MYOSARCOMA or LEIOMYOMA.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.

The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.

A connective tissue neoplasm formed by proliferation of mesodermal cells; it is usually highly malignant.

Elements of limited time intervals, contributing to particular results or situations.

A non-neoplastic inflammatory lesion, usually of the jaw or gingiva, containing large, multinucleated cells. It includes reparative giant cell granuloma. Peripheral giant cell granuloma refers to the gingiva (giant cell epulis); central refers to the jaw.

A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)

7,12-Dimethylbenzanthracene. Polycyclic aromatic hydrocarbon found in tobacco smoke that is a potent carcinogen.

Tracheal neoplasms are abnormal growths or tumors that develop within the trachea, which can be benign or malignant, and have the potential to obstruct the airway and impair respiratory function.

A transplantable, poorly differentiated malignant tumor which appeared originally as a spontaneous breast carcinoma in a mouse. It grows in both solid and ascitic forms.

Parotid diseases refer to a range of medical conditions that affect the structure, function, or health of the parotid glands, which are the largest salivary glands located in the face, near the ears, and responsible for producing saliva.

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

A sarcoma derived from deep fibrous tissue, characterized by bundles of immature proliferating fibroblasts with variable collagen formation, which tends to invade locally and metastasize by the bloodstream. (Stedman, 25th ed)

Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)

Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.

Antibodies produced by a single clone of cells.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.

Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)

A malignant cystic or semisolid tumor most often occurring in the ovary. Rarely, one is solid. This tumor may develop from a mucinous cystadenoma, or it may be malignant at the onset. The cysts are lined with tall columnar epithelial cells; in others, the epithelium consists of many layers of cells that have lost normal structure entirely. In the more undifferentiated tumors, one may see sheets and nests of tumor cells that have very little resemblance to the parent structure. (Hughes, Obstetric-Gynecologic Terminology, 1972, p184)

A CELL CYCLE and tumor growth marker which can be readily detected using IMMUNOCYTOCHEMISTRY methods. Ki-67 is a nuclear antigen present only in the nuclei of cycling cells.

Family of retrovirus-associated DNA sequences (ras) originally isolated from Harvey (H-ras, Ha-ras, rasH) and Kirsten (K-ras, Ki-ras, rasK) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both H-ras and K-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related N-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein.

A republic in western Africa, lying between GHANA on its west and BENIN on its east. Its capital is Lome.

A multilocular tumor with mucin secreting epithelium. They are most often found in the ovary, but are also found in the pancreas, appendix, and rarely, retroperitoneal and in the urinary bladder. They are considered to have low-grade malignant potential.

Mice homozygous for the mutant autosomal recessive gene "scid" which is located on the centromeric end of chromosome 16. These mice lack mature, functional lymphocytes and are thus highly susceptible to lethal opportunistic infections if not chronically treated with antibiotics. The lack of B- and T-cell immunity resembles severe combined immunodeficiency (SCID) syndrome in human infants. SCID mice are useful as animal models since they are receptive to implantation of a human immune system producing SCID-human (SCID-hu) hematochimeric mice.

A neural crest tumor usually derived from the chromoreceptor tissue of a paraganglion, such as the carotid body, or medulla of the adrenal gland (usually called a chromaffinoma or pheochromocytoma). It is more common in women than in men. (Stedman, 25th ed; from Segen, Dictionary of Modern Medicine, 1992)

Experimentally induced neoplasms of CONNECTIVE TISSUE in animals to provide a model for studying human SARCOMA.

A normal developing tooth which has not yet perforated the oral mucosa or one that fails to erupt in the normal sequence or time interval expected for the type of tooth in a given gender, age, or population group.

The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones.

Hereditary disorder consisting of multiple basal cell carcinomas, odontogenic keratocysts, and multiple skeletal defects, e.g., frontal and temporoparietal bossing, bifurcated and splayed ribs, kyphoscoliosis, fusion of vertebrae, and cervicothoracic spina bifida. Genetic transmission is autosomal dominant.

A usually benign, well-encapsulated, lobular, vascular tumor of chromaffin tissue of the ADRENAL MEDULLA or sympathetic paraganglia. The cardinal symptom, reflecting the increased secretion of EPINEPHRINE and NOREPINEPHRINE, is HYPERTENSION, which may be persistent or intermittent. During severe attacks, there may be HEADACHE; SWEATING, palpitation, apprehension, TREMOR; PALLOR or FLUSHING of the face, NAUSEA and VOMITING, pain in the CHEST and ABDOMEN, and paresthesias of the extremities. The incidence of malignancy is as low as 5% but the pathologic distinction between benign and malignant pheochromocytomas is not clear. (Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1298)