Leptomeningeal dissemination of low-grade gliomas in childhood.

Although leptomeningeal spread (LMS) of primary CNS tumors in children has been well documented in the literature, it has rarely been reported in children with low-grade gliomas. Between 1975 and 1985, 6 of 162 children (3.7%) with low-grade gliomas treated at Children's Hospital of Philadelphia had LMS. LMS was present at diagnosis of the original tumor in one patient, was the first sign of relapse in one patient, occurred simultaneously with local relapse in two patients, and after local relapse in two patients. Pathology of the original tumor was low-grade astrocytoma in five and low-grade oligodendroglioma in one. Primary tumor site was cervical cord in three, chiasm in one, frontal lobe in one, and cerebellum in one. All of the children with LMS had undergone surgical treatment at the time of diagnosis of the primary tumor; four had total resections at some point in their course. Three of the six patients died; three are still alive after treatment with radiation therapy and/or chemotherapy. The longest survival to date has been 3 1/2 years after diagnosis of LMS. We compared clinical characteristics of these six patients with 131 children with low-grade tumors without dissemination treated at our institution during the same time period. LMS, although relatively infrequent, does occur in children with low-grade gliomas, especially spinal cord tumors. LMS may occur at any time during illness and diagnosis may be difficult unless LMS is suspected. Treatment, at times, results in clinical improvement and considerable disease control.