Idiopathic isosexual central precocious puberty: magnetic resonance findings in 30 patients.

The purpose of this prospective study was to define the incidence of magnetic resonance imaging (MRI) abnormalities in the brain in patients with idiopathic central precocious puberty without any additional neurological signs and symptoms, and to evaluate the routine use of gadolinium contrast in these patients. 30 patients (29 girls, one boy; age range 1.9-11.9 years) with idiopathic central precocious puberty were studied. MRI of the brain in axial, coronal and sagittal planes was performed before and after administration of gadopentetate dimeglumine, with special attention to the region of the third ventricle. There are three major findings: (1) the height of the pituitary gland is increased up to adult size compared with normal individuals; (2) in four patients (13%) major structural abnormalities were found; three hamartomas of the tuber cinereum and one gliomatous process extending from the chiasm to the optic tract; and (3) the routine use of gadopentetate dimeglumine did not reveal new abnormalities although the lack of enhancement made a positive contribution to diagnostic certainty. We conclude that contrast enhanced MR examination is a safe and reliable method for the exclusion of abnormalities in children with precocious puberty and for the follow-up of those patients in whom abnormalities are present.