Dictionary

Cchordoma [kor doe´ ma] A rare, benign, extradural tumoroccurring at the base of the skull, or at the end of the spine.choriocarcinoma See germ cell tumor.choroid plexus [ko´ royd • pleks´ sus] Areas in the ventricleswhere cerebrospinal fluid is formed.choroid plexus carcinoma [ko´ royd • pleks´ sus • kar sih no´ ma]Occurring primarily in children, this is the malignant form ofthe choroid plexus papilloma. It comprises about ten percentof all choroid plexus tumors and typically occurs in one of thelateral ventricles. Also called anaplastic choroid plexuspapilloma.choroid plexus papilloma [ko´ royd • pleks´ sus • pap ih low´ ma]A rare, benign tumor most common in children under the ageof two. The lateral ventricles are the most common locationin young children, the fourth ventricle is the most commonsite in adults.chromosome [crow´ moe soam] Structures in the nucleus of acell that carry genes. All human cells contain 46 chromosomes(23 pair). Chromosomes are composed of DNA.chromosome deletion A portion of a chromosome is missing atleast one gene.chronic A disease or condition that persists over a long period oftime. Not acute.cingulate cortex [sin´ gyou lat • kor´ teks] A bundle of nervefibers in the white matter located over the surface of the corpuscallosum.circumscribed [sir´ come skribd] Having a border, localized.Often associated with a capsule and benign tumors of the brain,for example, meningiomas, pituitary adenomas and acousticneuromas.CIS Cancer Information Service. A service of the NationalCancer Institute, it is a national information network forpatients, the public and health professionals. CancerInformation Service provides the latest cancer informationthrough a toll-free telephone service, and can respond inEnglish or Spanish. Access by phone: 1-800-422-6237;TTY 1-800-332-8615.classification A system for grouping tumors based on sharedcharacteristics. Brain tumors are classified by their microscopicanatomy on the assumption that each kind of tumor resultsfrom the abnormal growth of a specific cell type. Classificationis thought to help predict a tumor’s behavior, the patient’sprognosis and to serve as a guide to treatment.clear cell ependymoma [ep en dih moe´ ma] A low grade tumormost commonly located in the fourth ventricle and the midline.clinical That which can be observed in or involves patients.Research treatments tested on patients, as opposed tolaboratory or animal testing.clinical cooperative group A network of physicians from variousmedical institutions investigating new treatments by planningand implementing research studies. Because of the relativerarity of brain tumors, most doctors and hospitals could notenter sufficient numbers of patients into a protocol (clinicaltrial) to derive meaningful data or it would take a very longtime to do so. Clinical cooperative groups and consortia werecreated by the National Cancer Institute so that newtreatments could be evaluated quickly.clinical investigator A physician who administers treatmentsbeing studied in clinical trials.Clinical Nurse Specialist A registered nurse with a master’sdegree in nursing who has demonstrated a high degree ofknowledge, skill and competence in a specialized area ofclinical nursing.C2425