There is a variety of tumors affecting the pituitary gland in childhood; some of these tumors (eg craniopharyngioma) are included among the most common central nervous system tumors in childhood. The gene(s) involved in the pathogenesis of these tumors are largely not known; their possible association with other developmental defects or inheritance pattern(s) has not been investigated. The present study serves as a (i) screening/training, and, (ii) a research protocol. As a screening and training study, this protocol allows our Institute to admit children with tumors of the hypothalamic-pituitary unit to the pediatric endocrine clinics and wards of the NIH Clinical Center for the purposes of (i) training our fellows and students in the identification of genetic defects associated with pituitary tumor formation, and (ii) teaching our fellows and students the recognition, management and complications of pituitary tumors As a research study, this protocol aims at (i) developing new clinical studies for the recognition and therapy of pituitary tumors; as an example, two new studies have emerged within the context of this protocol: (a) investigation of a new research magnetic resonance imaging (MRI) tool and its usefulness in the identification of pituitary tumors, and (b) investigation of the psychological effects of cortisol secretion in pediatric patients with Cushing disease. Continuation of this protocol will eventually lead to new, separate protocols that will address all aspects of diagnosis of pituitary tumors and their therapy in childhood. (ii) Identifying the genetic components of pituitary oncogenesis; those will be investigated by (a) studying the inheritance pattern of pituitary tumors in childhood and their possible association with other conditions in the families of the patients, and (ii) collecting tumor tissues and examining their molecular genetics. As with the clinical studies, the present protocol may help generate ideas for future studies on the treatment and clinical follow up of pediatric patients with tumors of the pituitary gland and, thus, lead to the development of better therapeutic regimens for these neoplasms....