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)Adrenal Gland Neoplasms: Tumors or cancer of the ADRENAL GLANDS.Metanephrine: Product of epinephrine O-methylation. It is a commonly occurring, pharmacologically and physiologically inactive metabolite of epinephrine.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.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)3-Iodobenzylguanidine: A guanidine analog with specific affinity for tissues of the sympathetic nervous system and related tumors. The radiolabeled forms are used as antineoplastic agents and radioactive imaging agents. (Merck Index, 12th ed) MIBG serves as a neuron-blocking agent which has a strong affinity for, and retention in, the adrenal medulla and also inhibits ADP-ribosyltransferase.Normetanephrine: A methylated metabolite of norepinephrine that is excreted in the urine and found in certain tissues. It is a marker for tumors.Multiple Endocrine Neoplasia Type 2a: A form of multiple endocrine neoplasia characterized by the presence of medullary carcinoma (CARCINOMA, MEDULLARY) of the THYROID GLAND, and usually with the co-occurrence of PHEOCHROMOCYTOMA, producing CALCITONIN and ADRENALINE, respectively. Less frequently, it can occur with hyperplasia or adenoma of the PARATHYROID GLANDS. This disease is due to gain-of-function mutations of the MEN2 gene on CHROMOSOME 10 (Locus: 10q11.2), also known as the RET proto-oncogene that encodes a RECEPTOR PROTEIN-TYROSINE KINASE. It is an autosomal dominant inherited disease.Catecholamines: A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.Paraganglioma, Extra-Adrenal: A relatively rare, usually benign neoplasm originating in the chemoreceptor tissue of the CAROTID BODY; GLOMUS JUGULARE; GLOMUS TYMPANICUM; AORTIC BODIES; and the female genital tract. It consists histologically of rounded or ovoid hyperchromatic cells that tend to be grouped in an alveolus-like pattern within a scant to moderate amount of fibrous stroma and a few large thin-walled vascular channels. (From Stedman, 27th ed)Adrenalectomy: Excision of one or both adrenal glands. (From Dorland, 28th ed)von Hippel-Lindau Disease: An autosomal dominant disorder caused by mutations in a tumor suppressor gene. This syndrome is characterized by abnormal growth of small blood vessels leading to a host of neoplasms. They include HEMANGIOBLASTOMA in the RETINA; CEREBELLUM; and SPINAL CORD; PHEOCHROMOCYTOMA; pancreatic tumors; and renal cell carcinoma (see CARCINOMA, RENAL CELL). Common clinical signs include HYPERTENSION and neurological dysfunctions.IodobenzenesVanilmandelic AcidNerve Growth Factors: Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.Succinate Dehydrogenase: A flavoprotein containing oxidoreductase that catalyzes the dehydrogenation of SUCCINATE to fumarate. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.Multiple Endocrine Neoplasia: A group of autosomal dominant diseases characterized by the combined occurrence of tumors involving two or more ENDOCRINE GLANDS that secrete PEPTIDE HORMONES or AMINES. These neoplasias are often benign but can be malignant. They are classified by the endocrine glands involved and the degree of aggressiveness. The two major forms are MEN1 and MEN2 with gene mutations on CHROMOSOME 11 and CHROMOSOME 10, respectively.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.Ganglioneuroma: A benign neoplasm that usually arises from the sympathetic trunk in the mediastinum. Histologic features include spindle cell proliferation (resembling a neurofibroma) and the presence of large ganglion cells. The tumor may present clinically with HORNER SYNDROME or diarrhea due to ectopic production of vasoactive intestinal peptide. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p966)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.Neurites: In tissue culture, hairlike projections of neurons stimulated by growth factors and other molecules. These projections may go on to form a branched tree of dendrites or a single axon or they may be reabsorbed at a later stage of development. "Neurite" may refer to any filamentous or pointed outgrowth of an embryonal or tissue-culture neural cell.Proto-Oncogene Proteins c-ret: Receptor protein-tyrosine kinases involved in the signaling of GLIAL CELL-LINE DERIVED NEUROTROPHIC FACTOR ligands. They contain an extracellular cadherin domain and form a receptor complexes with GDNF RECEPTORS. Mutations in ret protein are responsible for HIRSCHSPRUNG DISEASE and MULTIPLE ENDOCRINE NEOPLASIA TYPE 2.Nerve Growth Factor: NERVE GROWTH FACTOR is the first of a series of neurotrophic factors that were found to influence the growth and differentiation of sympathetic and sensory neurons. It is comprised of alpha, beta, and gamma subunits. The beta subunit is responsible for its growth stimulating activity.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)Adrenal Medulla: The inner portion of the adrenal gland. Derived from ECTODERM, adrenal medulla consists mainly of CHROMAFFIN CELLS that produces and stores a number of NEUROTRANSMITTERS, mainly adrenaline (EPINEPHRINE) and NOREPINEPHRINE. The activity of the adrenal medulla is regulated by the SYMPATHETIC NERVOUS SYSTEM.Abdominal NeoplasmsGerm-Line Mutation: Any detectable and heritable alteration in the lineage of germ cells. Mutations in these cells (i.e., "generative" cells ancestral to the gametes) are transmitted to progeny while those in somatic cells are not.Iodine Radioisotopes: Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.Pregnancy Complications, Neoplastic: The co-occurrence of pregnancy and NEOPLASMS. The neoplastic disease may precede or follow FERTILIZATION.Von Hippel-Lindau Tumor Suppressor Protein: A ubiquitin-protein ligase that mediates OXYGEN-dependent polyubiquitination of HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. It is inactivated in VON HIPPEL-LINDAU SYNDROME.Norepinephrine: Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.Multiple Endocrine Neoplasia Type 2b: Similar to MEN2A, it is also caused by mutations of the MEN2 gene, also known as the RET proto-oncogene. Its clinical symptoms include medullary carcinoma (CARCINOMA, MEDULLARY) of THYROID GLAND and PHEOCHROMOCYTOMA of ADRENAL MEDULLA (50%). Unlike MEN2a, MEN2b does not involve PARATHYROID NEOPLASMS. It can be distinguished from MEN2A by its neural abnormalities such as mucosal NEUROMAS on EYELIDS; LIP; and TONGUE, and ganglioneuromatosis of GASTROINTESTINAL TRACT leading to MEGACOLON. It is an autosomal dominant inherited disease.Neurofibromatosis 1: 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).Adrenal Glands: A pair of glands located at the cranial pole of each of the two KIDNEYS. Each adrenal gland is composed of two distinct endocrine tissues with separate embryonic origins, the ADRENAL CORTEX producing STEROIDS and the ADRENAL MEDULLA producing NEUROTRANSMITTERS.Tyrosine 3-Monooxygenase: An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.2-Hydroxyphenethylamine: Simple amine found in the brain. It may be modulator of sympathetic functions. Its derivatives are adrenergic agonists and antagonists. It is also used in chemical industry.Adenoma, Acidophil: A benign tumor, usually found in the anterior lobe of the pituitary gland, whose cells stain with acid dyes. Such pituitary tumors may give rise to excessive secretion of growth hormone, resulting in gigantism or acromegaly. A specific type of acidophil adenoma may give rise to nonpuerperal galactorrhea. (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.Dihydroxyphenylalanine: A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.Thyroid Neoplasms: Tumors or cancer of the THYROID GLAND.Adrenal Gland Diseases: Pathological processes of the ADRENAL GLANDS.Incidental Findings: Unanticipated information discovered in the course of testing or medical care. Used in discussions of information that may have social or psychological consequences, such as when it is learned that a child's biological father is someone other than the putative father, or that a person tested for one disease or disorder has, or is at risk for, something else.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Dopamine: One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.Dopamine beta-HydroxylaseRadiopharmaceuticals: 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)Neoplasms, Complex and Mixed: Neoplasms composed of more than one type of neoplastic tissue.