Neuroendocrine Tumors: 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.Carcinoma, Neuroendocrine: A group of carcinomas which share a characteristic morphology, often being composed of clusters and trabecular sheets of round "blue cells", granular chromatin, and an attenuated rim of poorly demarcated cytoplasm. Neuroendocrine tumors include carcinoids, small ("oat") cell carcinomas, medullary carcinoma of the thyroid, Merkel cell tumor, cutaneous neuroendocrine carcinoma, pancreatic islet cell tumors, and pheochromocytoma. Neurosecretory granules are found within the tumor cells. (Segen, Dictionary of Modern Medicine, 1992)Carcinoma: A malignant neoplasm made up of epithelial cells tending to infiltrate the surrounding tissues and give rise to metastases. It is a histological type of neoplasm but is often wrongly used as a synonym for "cancer." (From Dorland, 27th ed)Neurosecretory Systems: A system of NEURONS that has the specialized function to produce and secrete HORMONES, and that constitutes, in whole or in part, an ENDOCRINE SYSTEM or organ.Neuroendocrine Cells: Specialized NEURONS that produce hormones, such as NEUROPEPTIDES or BIOGENIC AMINES. They generally are in the NERVOUS SYSTEM, such as HYPOTHALAMUS, but can be found in other organs or systems. These neurons contain dense neurosecretory granules and PROPROTEIN CONVERTASES allowing the rapidly release of NEUROHORMONES into the blood circulation upon stimulation.Carcinoma, Squamous Cell: 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)Carcinoma, Hepatocellular: A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.Chromogranin A: A type of chromogranin which was first isolated from CHROMAFFIN CELLS of the ADRENAL MEDULLA but is also found in other tissues and in many species including human, bovine, rat, mouse, and others. It is an acidic protein with 431 to 445 amino acid residues. It contains fragments that inhibit vasoconstriction or release of hormones and neurotransmitter, while other fragments exert antimicrobial actions.Carcinoma in Situ: A lesion with cytological characteristics associated with invasive carcinoma but the tumor cells are confined to the epithelium of origin, without invasion of the basement membrane.Chromogranins: A group of acidic proteins that are major components of SECRETORY GRANULES in the endocrine and neuroendocrine cells. They play important roles in the aggregation, packaging, sorting, and processing of secretory protein prior to secretion. They are cleaved to release biologically active peptides. There are various types of granins, usually classified by their sources.Carcinoid Tumor: 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)Carcinoma, Papillary: A malignant neoplasm characterized by the formation of numerous, irregular, finger-like projections of fibrous stroma that is covered with a surface layer of neoplastic epithelial cells. (Stedman, 25th ed)Liver Neoplasms: Tumors or cancer of the LIVER.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Carcinoma, Small Cell: An anaplastic, highly malignant, and usually bronchogenic carcinoma composed of small ovoid cells with scanty neoplasm. It is characterized by a dominant, deeply basophilic nucleus, and absent or indistinct nucleoli. (From Stedman, 25th ed; Holland et al., Cancer Medicine, 3d ed, p1286-7)Carcinoma, Ductal, Breast: An invasive (infiltrating) CARCINOMA of the mammary ductal system (MAMMARY GLANDS) in the human BREAST.Carcinoma, Basal Cell: A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)Tumor Markers, Biological: 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.Pancreatic Neoplasms: 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).Neuroendocrine Secretory Protein 7B2: An acidic protein found in the NEUROENDOCRINE SYSTEM that functions as a molecular chaperone for PROPROTEIN CONVERTASE 2.Carcinoma, Large Cell: A tumor of undifferentiated (anaplastic) cells of large size. It is usually bronchogenic. (From Dorland, 27th ed)Lung Neoplasms: Tumors or cancer of the LUNG.Carcinoma, Medullary: A carcinoma composed mainly of epithelial elements with little or no stroma. Medullary carcinomas of the breast constitute 5%-7% of all mammary carcinomas; medullary carcinomas of the thyroid comprise 3%-10% of all thyroid malignancies. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1141; Segen, Dictionary of Modern Medicine, 1992)Carcinoma, Merkel Cell: A carcinoma arising from MERKEL CELLS located in the basal layer of the epidermis and occurring most commonly as a primary neuroendocrine carcinoma of the skin. Merkel cells are tactile cells of neuroectodermal origin and histologically show neurosecretory granules. The skin of the head and neck are a common site of Merkel cell carcinoma, occurring generally in elderly patients. (Holland et al., Cancer Medicine, 3d ed, p1245)Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Gastrointestinal Neoplasms: Tumors or cancer of the GASTROINTESTINAL TRACT, from the MOUTH to the ANAL CANAL.Carcinoma, Bronchogenic: Malignant neoplasm arising from the epithelium of the BRONCHI. It represents a large group of epithelial lung malignancies which can be divided into two clinical groups: SMALL CELL LUNG CANCER and NON-SMALL-CELL LUNG CARCINOMA.Carcinoma, Transitional Cell: A malignant neoplasm derived from TRANSITIONAL EPITHELIAL CELLS, occurring chiefly in the URINARY BLADDER; URETERS; or RENAL PELVIS.Synaptophysin: A MARVEL domain-containing protein found in the presynaptic vesicles of NEURONS and NEUROENDOCRINE CELLS. It is commonly used as an immunocytochemical marker for neuroendocrine differentiation.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Cell Line, Tumor: A cell line derived from cultured tumor cells.Octreotide: A potent, long-acting synthetic SOMATOSTATIN octapeptide analog that inhibits secretion of GROWTH HORMONE and is used to treat hormone-secreting tumors; DIABETES MELLITUS; HYPOTENSION, ORTHOSTATIC; HYPERINSULINISM; hypergastrinemia; and small bowel fistula.Thyroid Neoplasms: Tumors or cancer of the THYROID GLAND.Carcinoma, Intraductal, Noninfiltrating: A noninvasive (noninfiltrating) carcinoma of the breast characterized by a proliferation of malignant epithelial cells confined to the mammary ducts or lobules, without light-microscopy evidence of invasion through the basement membrane into the surrounding stroma.Carcinoma, Adenoid Cystic: Carcinoma characterized by bands or cylinders of hyalinized or mucinous stroma separating or surrounded by nests or cords of small epithelial cells. When the cylinders occur within masses of epithelial cells, they give the tissue a perforated, sievelike, or cribriform appearance. Such tumors occur in the mammary glands, the mucous glands of the upper and lower respiratory tract, and the salivary glands. They are malignant but slow-growing, and tend to spread locally via the nerves. (Dorland, 27th ed)Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Gene Expression Regulation, Neoplastic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.Neoplasm Invasiveness: Ability of neoplasms to infiltrate and actively destroy surrounding tissue.Carcinoma, Lobular: A infiltrating (invasive) breast cancer, relatively uncommon, accounting for only 5%-10% of breast tumors in most series. It is often an area of ill-defined thickening in the breast, in contrast to the dominant lump characteristic of ductal carcinoma. It is typically composed of small cells in a linear arrangement with a tendency to grow around ducts and lobules. There is likelihood of axillary nodal involvement with metastasis to meningeal and serosal surfaces. (DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1205)Breast Neoplasms: Tumors or cancer of the human BREAST.Nasopharyngeal Neoplasms: Tumors or cancer of the NASOPHARYNX.Receptors, Somatostatin: Cell surface proteins that bind somatostatin and trigger intracellular changes which influence the behavior of cells. Somatostatin is a hypothalamic hormone, a pancreatic hormone, and a central and peripheral neurotransmitter. Activated somatostatin receptors on pituitary cells inhibit the release of growth hormone; those on endocrine and gastrointestinal cells regulate the absorption and utilization of nutrients; and those on neurons mediate somatostatin's role as a neurotransmitter.Bronchial Neoplasms: Tumors or cancer of the BRONCHI.Digestive System Neoplasms: Tumors or cancer of the DIGESTIVE SYSTEM.Carcinoma, Mucoepidermoid: A tumor of both low- and high-grade malignancy. The low-grade grow slowly, appear in any age group, and are readily cured by excision. The high-grade behave aggressively, widely infiltrate the salivary gland and produce lymph node and distant metastases. Mucoepidermoid carcinomas account for about 21% of the malignant tumors of the parotid gland and 10% of the sublingual gland. They are the most common malignant tumor of the parotid. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p575; Holland et al., Cancer Medicine, 3d ed, p1240)Lymphatic Metastasis: Transfer of a neoplasm from its primary site to lymph nodes or to distant parts of the body by way of the lymphatic system.Carcinoma, Adenosquamous: A mixed adenocarcinoma and squamous cell or epidermoid carcinoma.Neoplasm Metastasis: The transfer of a neoplasm from one organ or part of the body to another remote from the primary site.RNA, Messenger: 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.Stomach Neoplasms: Tumors or cancer of the STOMACH.Head and Neck Neoplasms: Soft tissue tumors or cancer arising from the mucosal surfaces of the LIP; oral cavity; PHARYNX; LARYNX; and cervical esophagus. Other sites included are the NOSE and PARANASAL SINUSES; SALIVARY GLANDS; THYROID GLAND and PARATHYROID GLANDS; and MELANOMA and non-melanoma skin cancers of the head and neck. (from Holland et al., Cancer Medicine, 4th ed, p1651)Hypothalamo-Hypophyseal System: A collection of NEURONS, tracts of NERVE FIBERS, endocrine tissue, and blood vessels in the HYPOTHALAMUS and the PITUITARY GLAND. This hypothalamo-hypophyseal portal circulation provides the mechanism for hypothalamic neuroendocrine (HYPOTHALAMIC HORMONES) regulation of pituitary function and the release of various PITUITARY HORMONES into the systemic circulation to maintain HOMEOSTASIS.Neoplasms, Multiple Primary: 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.Carcinoma, Endometrioid: An adenocarcinoma characterized by the presence of cells resembling the glandular cells of the ENDOMETRIUM. It is a common histological type of ovarian CARCINOMA and ENDOMETRIAL CARCINOMA. There is a high frequency of co-occurrence of this form of adenocarcinoma in both tissues.Somatostatin: A 14-amino acid peptide named for its ability to inhibit pituitary GROWTH HORMONE release, also called somatotropin release-inhibiting factor. It is expressed in the central and peripheral nervous systems, the gut, and other organs. SRIF can also inhibit the release of THYROID-STIMULATING HORMONE; PROLACTIN; INSULIN; and GLUCAGON besides acting as a neurotransmitter and neuromodulator. In a number of species including humans, there is an additional form of somatostatin, SRIF-28 with a 14-amino acid extension at the N-terminal.Retrospective Studies: 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.Hypothalamus: Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.Neoplasm Proteins: 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.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.Carcinoma, Embryonal: A highly malignant, primitive form of carcinoma, probably of germinal cell or teratomatous derivation, usually arising in a gonad and rarely in other sites. It is rare in the female ovary, but in the male it accounts for 20% of all testicular tumors. (From Dorland, 27th ed & Holland et al., Cancer Medicine, 3d ed, p1595)Esophageal Neoplasms: Tumors or cancer of the ESOPHAGUS.Intestinal Neoplasms: Tumors or cancer of the INTESTINES.Treatment Outcome: 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.Mouth Neoplasms: Tumors or cancer of the MOUTH.Immunoenzyme Techniques: 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.Skin Neoplasms: Tumors or cancer of the SKIN.Carcinoma, Ductal: Malignant neoplasms involving the ductal systems of any of a number of organs, such as the MAMMARY GLANDS, the PANCREAS, the PROSTATE, or the LACRIMAL GLAND.Ovarian Neoplasms: 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.Chromogranin B: A type of chromogranin which was initially characterized in a rat PHEOCHROMOCYTOMA CELL LINE. It is found in many species including human, rat, mouse, and others. It is an acidic protein with 626 to 657 amino acid residues. In some species, it inhibits secretion of PARATHYROID HORMONE or INSULIN and exerts bacteriolytic effects in others.Colonic Neoplasms: Tumors or cancer of the COLON.Mice, Nude: 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.Laryngeal Neoplasms: Cancers or tumors of the LARYNX or any of its parts: the GLOTTIS; EPIGLOTTIS; LARYNGEAL CARTILAGES; LARYNGEAL MUSCLES; and VOCAL CORDS.Urinary Bladder Neoplasms: Tumors or cancer of the URINARY BLADDER.Phosphopyruvate Hydratase: A hydro-lyase that catalyzes the dehydration of 2-phosphoglycerate to form PHOSPHOENOLPYRUVATE. Several different isoforms of this enzyme exist, each with its own tissue specificity.Adrenocortical Carcinoma: A malignant neoplasm of the ADRENAL CORTEX. Adrenocortical carcinomas are unencapsulated anaplastic (ANAPLASIA) masses sometimes exceeding 20 cm or 200 g. They are more likely to be functional than nonfunctional, and produce ADRENAL CORTEX HORMONES that may result in hypercortisolism (CUSHING SYNDROME); HYPERALDOSTERONISM; and/or VIRILISM.Neoplasm Recurrence, Local: 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.Carcinoma, Verrucous: A variant of well-differentiated epidermoid carcinoma that is most common in the oral cavity, but also occurs in the larynx, nasal cavity, esophagus, penis, anorectal region, vulva, vagina, uterine cervix, and skin, especially on the sole of the foot. Most intraoral cases occur in elderly male abusers of smokeless tobacco. The treatment is surgical resection. Radiotherapy is not indicated, as up to 30% treated with radiation become highly aggressive within six months. (Segen, Dictionary of Modern Medicine, 1992)DNA, Neoplasm: DNA present in neoplastic tissue.Reverse Transcriptase Polymerase Chain Reaction: 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.Carcinoma, Signet Ring Cell: A poorly differentiated adenocarcinoma in which the nucleus is pressed to one side by a cytoplasmic droplet of mucus. It usually arises in the gastrointestinal system.Survival Rate: The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.Survival Analysis: A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.Pituitary-Adrenal System: The interactions between the anterior pituitary and adrenal glands, in which corticotropin (ACTH) stimulates the adrenal cortex and adrenal cortical hormones suppress the production of corticotropin by the anterior pituitary.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Ileal Neoplasms: Tumors or cancer in the ILEUM region of the small intestine (INTESTINE, SMALL).Adenocarcinoma, Mucinous: An adenocarcinoma producing mucin in significant amounts. (From Dorland, 27th ed)Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Adrenocorticotropic Hormone: An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).Uterine Cervical Neoplasms: Tumors or cancer of the UTERINE CERVIX.Neoplasm Transplantation: Experimental transplantation of neoplasms in laboratory animals for research purposes.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Gallbladder Neoplasms: Tumors or cancer of the gallbladder.Hydrocortisone: The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions.Disease Progression: 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.Ki-67 Antigen: 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.Antigens, Neoplasm: 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.Neuropeptides: Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.Carcinoma, Non-Small-Cell Lung: A heterogeneous aggregate of at least three distinct histological types of lung cancer, including SQUAMOUS CELL CARCINOMA; ADENOCARCINOMA; and LARGE CELL CARCINOMA. They are dealt with collectively because of their shared treatment strategy.Neoplasms, Complex and Mixed: Neoplasms composed of more than one type of neoplastic tissue.Endocrine Gland Neoplasms: Tumors or cancer of the ENDOCRINE GLANDS.Combined Modality Therapy: The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.Keratins: A class of fibrous proteins or scleroproteins that represents the principal constituent of EPIDERMIS; HAIR; NAILS; horny tissues, and the organic matrix of tooth ENAMEL. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of TYPE I KERATIN and a TYPE II KERATIN, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. alpha-Keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to GENE DUPLICATION.Endocrine Glands: Ductless glands that secrete HORMONES directly into the BLOOD CIRCULATION. These hormones influence the METABOLISM and other functions of cells in the body.Corticosterone: An adrenocortical steroid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. (From Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1437)Tumor Suppressor Protein p53: 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.Precancerous Conditions: Pathological processes that tend eventually to become malignant. (From Dorland, 27th ed)Adenocarcinoma, Follicular: An adenocarcinoma of the thyroid gland, in which the cells are arranged in the form of follicles. (From Dorland, 27th ed)Vipoma: A tumor that secretes VASOACTIVE INTESTINAL PEPTIDE, a neuropeptide that causes VASODILATION; relaxation of smooth muscles; watery DIARRHEA; HYPOKALEMIA; and HYPOCHLORHYDRIA. Vipomas, derived from the pancreatic ISLET CELLS, generally are malignant and can secrete other hormones. In most cases, Vipomas are located in the PANCREAS but can be found in extrapancreatic sites.Signal Transduction: 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.Common Bile Duct Neoplasms: Tumor or cancer of the COMMON BILE DUCT including the AMPULLA OF VATER and the SPHINCTER OF ODDI.Proprotein Convertase 2: A serine endopeptidase that has specificity for cleavage at ARGININE. It cleaves a variety of prohormones including PRO-OPIOMELANOCORTIN, proluteinizing-hormone-releasing hormone, proenkephalins, prodynorphin, and PROINSULIN.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Molecular Sequence Data: 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.Tissue Array Analysis: The simultaneous analysis of multiple samples of TISSUES or CELLS from BIOPSY or in vitro culture that have been arranged in an array format on slides or microchips.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Disease-Free Survival: Period after successful treatment in which there is no appearance of the symptoms or effects of the disease.Ampulla of Vater: A dilation of the duodenal papilla that is the opening of the juncture of the COMMON BILE DUCT and the MAIN PANCREATIC DUCT, also known as the hepatopancreatic ampulla.Carcinoma, Islet Cell: A primary malignant neoplasm of the pancreatic ISLET CELLS. Usually it involves the non-INSULIN-producing cell types, the PANCREATIC ALPHA CELLS and the pancreatic delta cells (SOMATOSTATIN-SECRETING CELLS) in GLUCAGONOMA and SOMATOSTATINOMA, respectively.Embryonal Carcinoma Stem Cells: The malignant stem cells of TERATOCARCINOMAS, which resemble pluripotent stem cells of the BLASTOCYST INNER CELL MASS. The EC cells can be grown in vitro, and experimentally induced to differentiate. They are used as a model system for studying early embryonic cell differentiation.Colorectal Neoplasms: Tumors or cancer of the COLON or the RECTUM or both. Risk factors for colorectal cancer include chronic ULCERATIVE COLITIS; FAMILIAL POLYPOSIS COLI; exposure to ASBESTOS; and irradiation of the CERVIX UTERI.Radiopharmaceuticals: Compounds that are used in medicine as sources of radiation for radiotherapy and for diagnostic purposes. They have numerous uses in research and industry. (Martindale, The Extra Pharmacopoeia, 30th ed, p1161)Follow-Up Studies: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Mutation: 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.Secretory Vesicles: Vesicles derived from the GOLGI APPARATUS containing material to be released at the cell surface.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Kaplan-Meier Estimate: A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)Carcinoma, Papillary, Follicular: A thyroid neoplasm of mixed papillary and follicular arrangement. Its biological behavior and prognosis is the same as that of a papillary adenocarcinoma of the thyroid. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1271)Pheochromocytoma: 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)Chemoembolization, Therapeutic: Administration of antineoplastic agents together with an embolizing vehicle. This allows slow release of the agent as well as obstruction of the blood supply to the neoplasm.Gastrinoma: A GASTRIN-secreting neuroendocrine tumor of the non-beta ISLET CELLS, the GASTRIN-SECRETING CELLS. This type of tumor is primarily located in the PANCREAS or the DUODENUM. Majority of gastrinomas are malignant. They metastasize to the LIVER; LYMPH NODES; and BONE but rarely elsewhere. The presence of gastrinoma is one of three requirements to be met for identification of ZOLLINGER-ELLISON SYNDROME, which sometimes occurs in families with MULTIPLE ENDOCRINE NEOPLASIA TYPE 1; (MEN 1).Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Cell Transformation, Neoplastic: 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.RNA, Neoplasm: RNA present in neoplastic tissue.Endometrial Neoplasms: Tumors or cancer of ENDOMETRIUM, the mucous lining of the UTERUS. These neoplasms can be benign or malignant. Their classification and grading are based on the various cell types and the percent of undifferentiated cells.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Cisplatin: An inorganic and water-soluble platinum complex. After undergoing hydrolysis, it reacts with DNA to produce both intra and interstrand crosslinks. These crosslinks appear to impair replication and transcription of DNA. The cytotoxicity of cisplatin correlates with cellular arrest in the G2 phase of the cell cycle.Adenocarcinoma, Clear Cell: An adenocarcinoma characterized by the presence of varying combinations of clear and hobnail-shaped tumor cells. There are three predominant patterns described as tubulocystic, solid, and papillary. These tumors, usually located in the female reproductive organs, have been seen more frequently in young women since 1970 as a result of the association with intrauterine exposure to diethylstilbestrol. (From Holland et al., Cancer Medicine, 3d ed)Adrenal Gland Neoplasms: Tumors or cancer of the ADRENAL GLANDS.Nervous System Neoplasms: Benign and malignant neoplastic processes arising from or involving components of the central, peripheral, and autonomic nervous systems, cranial nerves, and meninges. Included in this category are primary and metastatic nervous system neoplasms.Corticotropin-Releasing Hormone: A peptide of about 41 amino acids that stimulates the release of ADRENOCORTICOTROPIC HORMONE. CRH is synthesized by neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, CRH stimulates the release of ACTH from the PITUITARY GLAND. CRH can also be synthesized in other tissues, such as PLACENTA; ADRENAL MEDULLA; and TESTIS.Transplantation, Heterologous: Transplantation between animals of different species.Small Cell Lung Carcinoma: A form of highly malignant lung cancer that is composed of small ovoid cells (SMALL CELL CARCINOMA).Endocrine System Diseases: Pathological processes of the ENDOCRINE GLANDS, and diseases resulting from abnormal level of available HORMONES.alpha-Fetoproteins: The first alpha-globulins to appear in mammalian sera during FETAL DEVELOPMENT and the dominant serum proteins in early embryonic life.Tongue Neoplasms: Tumors or cancer of the TONGUE.Pituitary Gland: A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM.Paraventricular Hypothalamic Nucleus: Nucleus in the anterior part of the HYPOTHALAMUS.Loss of Heterozygosity: The loss of one allele at a specific locus, caused by a deletion mutation; or loss of a chromosome from a chromosome pair, resulting in abnormal HEMIZYGOSITY. It is detected when heterozygous markers for a locus appear monomorphic because one of the ALLELES was deleted.Sensitivity and Specificity: 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)Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Cystadenocarcinoma, Serous: A malignant cystic or semicystic neoplasm. It often occurs in the ovary and usually bilaterally. The external surface is usually covered with papillary excrescences. Microscopically, the papillary patterns are predominantly epithelial overgrowths with differentiated and undifferentiated papillary serous cystadenocarcinoma cells. Psammoma bodies may be present. The tumor generally adheres to surrounding structures and produces ascites. (From Hughes, Obstetric-Gynecologic Terminology, 1972, p185)Carcinoma, Lewis Lung: A carcinoma discovered by Dr. Margaret R. Lewis of the Wistar Institute in 1951. This tumor originated spontaneously as a carcinoma of the lung of a C57BL mouse. The tumor does not appear to be grossly hemorrhagic and the majority of the tumor tissue is a semifirm homogeneous mass. (From Cancer Chemother Rep 2 1972 Nov;(3)1:325) It is also called 3LL and LLC and is used as a transplantable malignancy.PC12 Cells: A CELL LINE derived from a PHEOCHROMOCYTOMA of the rat ADRENAL MEDULLA. PC12 cells stop dividing and undergo terminal differentiation when treated with NERVE GROWTH FACTOR, making the line a useful model system for NERVE CELL differentiation.Thymus Neoplasms: Tumors or cancer of the THYMUS GLAND.Antineoplastic Combined Chemotherapy Protocols: The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.Hyperplasia: An increase in the number of cells in a tissue or organ without tumor formation. It differs from HYPERTROPHY, which is an increase in bulk without an increase in the number of cells.Neuroimmunomodulation: The biochemical and electrophysiological interactions between the NERVOUS SYSTEM and IMMUNE SYSTEM.Neoplasm Grading: Methods which attempt to express in replicable terms the level of CELL DIFFERENTIATION in neoplasms as increasing ANAPLASIA correlates with the aggressiveness of the neoplasm.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Duodenal Neoplasms: Tumors or cancer of the DUODENUM.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Tumor Burden: The total amount (cell number, weight, size or volume) of tumor cells or tissue in the body.Apudoma: A general term collectively applied to tumors associated with the APUD CELLS series, irrespective of their specific identification.Insulinoma: A benign tumor of the PANCREATIC BETA CELLS. Insulinoma secretes excess INSULIN resulting in HYPOGLYCEMIA.Pituitary Hormones: Hormones secreted by the PITUITARY GLAND including those from the anterior lobe (adenohypophysis), the posterior lobe (neurohypophysis), and the ill-defined intermediate lobe. Structurally, they include small peptides, proteins, and glycoproteins. They are under the regulation of neural signals (NEUROTRANSMITTERS) or neuroendocrine signals (HYPOTHALAMIC HORMONES) from the hypothalamus as well as feedback from their targets such as ADRENAL CORTEX HORMONES; ANDROGENS; ESTROGENS.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Hormones: Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.Prolactin: A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.Salivary Gland Neoplasms: Tumors or cancer of the SALIVARY GLANDS.Neoplasms, Unknown Primary: Metastases in which the tissue of origin is unknown.Pro-Opiomelanocortin: A 30-kDa protein synthesized primarily in the ANTERIOR PITUITARY GLAND and the HYPOTHALAMUS. It is also found in the skin and other peripheral tissues. Depending on species and tissues, POMC is cleaved by PROHORMONE CONVERTASES yielding various active peptides including ACTH; BETA-LIPOTROPIN; ENDORPHINS; MELANOCYTE-STIMULATING HORMONES; and others (GAMMA-LPH; CORTICOTROPIN-LIKE INTERMEDIATE LOBE PEPTIDE; N-terminal peptide of POMC or NPP).Rectal Neoplasms: Tumors or cancer of the RECTUM.Neoplasms, Nerve Tissue: Neoplasms composed of nerve tissue. This concept does not refer to neoplasms located in the nervous system or its component nerves.Glucagonoma: An almost always malignant GLUCAGON-secreting tumor derived from the PANCREATIC ALPHA CELLS. It is characterized by a distinctive migratory ERYTHEMA; WEIGHT LOSS; STOMATITIS; GLOSSITIS; DIABETES MELLITUS; hypoaminoacidemia; and normochromic normocytic ANEMIA.Neovascularization, Pathologic: A pathologic process consisting of the proliferation of blood vessels in abnormal tissues or in abnormal positions.Genes, p53: Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.Paraganglioma: 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)Cell Line: Established cell cultures that have the potential to propagate indefinitely.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Chromaffin Cells: Cells that store epinephrine secretory vesicles. During times of stress, the nervous system signals the vesicles to secrete their hormonal content. Their name derives from their ability to stain a brownish color with chromic salts. Characteristically, they are located in the adrenal medulla and paraganglia (PARAGANGLIA, CHROMAFFIN) of the sympathetic nervous system.Calcitonin: A peptide hormone that lowers calcium concentration in the blood. In humans, it is released by thyroid cells and acts to decrease the formation and absorptive activity of osteoclasts. Its role in regulating plasma calcium is much greater in children and in certain diseases than in normal adults.Paranasal Sinus Neoplasms: Tumors or cancer of the PARANASAL SINUSES.Carcinoembryonic Antigen: A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment.Neurosecretion: The production and release of substances such as NEUROTRANSMITTERS or HORMONES from nerve cells.Yttrium Radioisotopes: Unstable isotopes of yttrium that decay or disintegrate emitting radiation. Y atoms with atomic weights 82-88 and 90-96 are radioactive yttrium isotopes.Cadherins: Calcium-dependent cell adhesion proteins. They are important in the formation of ADHERENS JUNCTIONS between cells. Cadherins are classified by their distinct immunological and tissue specificities, either by letters (E- for epithelial, N- for neural, and P- for placental cadherins) or by numbers (cadherin-12 or N-cadherin 2 for brain-cadherin). Cadherins promote cell adhesion via a homophilic mechanism as in the construction of tissues and of the whole animal body.Oxytocin: A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.Thyroidectomy: Surgical removal of the thyroid gland. (Dorland, 28th ed)Receptor, erbB-2: A cell surface protein-tyrosine kinase receptor that is overexpressed in a variety of ADENOCARCINOMAS. It has extensive homology to and heterodimerizes with the EGF RECEPTOR, the ERBB-3 RECEPTOR, and the ERBB-4 RECEPTOR. Activation of the erbB-2 receptor occurs through heterodimer formation with a ligand-bound erbB receptor family member.Positron-Emission Tomography: An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.Gonadotropin-Releasing Hormone: A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Adenocarcinoma, Papillary: An adenocarcinoma containing finger-like processes of vascular connective tissue covered by neoplastic epithelium, projecting into cysts or the cavity of glands or follicles. It occurs most frequently in the ovary and thyroid gland. (Stedman, 25th ed)Down-Regulation: A negative regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.Tumor Suppressor Proteins: 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.Genes, Tumor Suppressor: 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.Carcinoma, Pancreatic Ductal: Carcinoma that arises from the PANCREATIC DUCTS. It accounts for the majority of cancers derived from the PANCREAS.