Optic pathway gliomas associated with neurofibromatosis type I in children

Abstract

Neurofibromatosis type I (NFI) is one of the most common brain tumor predisposition syndromes. Children with NFI are prone to develop a low grade gliomas, which can be localized in various areas of the brain, however, most of them occur in the structures of the optic pathway: optic nerves, chiasm, tracts and optic radiations – that is, are optic pathway gliomas (OPG). This retrospective study included children with newly diagnosied low grade glioma of the optic pathway at the age from 0 to 18 years with NFI, who underwent medical examination and/or treatment at the Burdenko Neurosurgery Institute from January 1, 2003 till December 31, 2015. A total from 264 patients 42 (16%) had clinical manifestations of NFI. The ratio of boys and girls was 1:1. The median age was 4.25 years (range 4.5 months – 17 years). Visual disturbances were the most frequent clinical manifestation of the tumor. Surgical resection was performed in 18 patients. The remaining 24 patients OPG were diagnosed based on clinical and radiological findings: 9 patients were in observation group, 11 patients chemotherapy was carried out, three were given radiation therapy, and spontaneous regression of the tumor was recorded in 1 patient. Progression of the disease was observed in 14 patients in our cohort. The overall survival rate in patients with NFI was 98 ± 2% at 5 years. Event free survival rate was 68 ± 7% at 5 years. The study was approved by the Independent Ethics Committee of N.N. Burdenko National Medical Research Center of neurosurgery Ministry of healthcare of Russian Federation.