percentage of study population developing pituitary tumors during a period of time percentage of study population developing pituitary tumors that replace the entire gland during a period of time 2013-06-11T18:29:59Z CMO:0001617 JSmith The number of individuals in a study population which develop new instances of pituitary gland tumors in which the neoplastic tissue completely eliminates and takes the place of all of the normal tissue in the pituitary gland during a specified period of time divided by the total number of individuals in the study population, expressed as a percentage. A tumor is an abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function. The pituitary gland is a small, oval endocrine gland attached to the base of the vertebrate brain and consisting of an anterior and posterior lobe, the secretions of which control the other endocrine glands and influence growth, metabolism, and maturation. VT:0010578 clinical_measurement_ontology incidence of pituitary tumors that replace the entire gland