Multicentric juvenile pilocytic astrocytoma occurring primarily in the trigone of the lateral ventricle

The authors report a juvenile pilocytic astrocytoma (JPA) in the trigone of an 11-year-old girl, apparently with disseminated lesions that disappeared spontaneously after the removal of primary lesion. Gadolinium-enhanced mag netic resonance images (MRIs) showed features suggestive of the development of multicentric spread of the tumor at the initial diagnosis. Histological ly the primary tumor showed the typical features of a JPA. Serial postopera tive MRIs demonstrated that everything except a remnant of the primary tumo r seemed to regress spontaneously without any adjuvant therapy. The site of origin of this tumor is thought to be the subependymal glia of the occipit al lobe.