Optic nerve glioma: case series with review of clinical, radiologic, molecular, and histopathologic characteristics.

PURPOSE: This study was designed to better understand the biologic nature of optic nerve gliomas (ONGs) and to investigate staining techniques that might improve the pathologic interpretation of surgical margins.

METHODS: In this retrospective case series, clinical data on patient presentation, MRI, surgical visualization, and initial pathologic interpretation were gathered. Specimens were then reexamined using analysis of p53, isocitrate dehydrogenase 1 (IDH1), MIB-1, and B-rapidly accelerated fibrosarcoma (BRAF) duplication.

RESULTS: Six patients were studied. All were diagnosed with World Health Organization grade 1 ONGs on original pathology. On reexamination, BRAF tandem duplication was found in 2 patients with neurofibromatosis Type 1 association. P53 immunoreactivity was noted in a third case. No cases had IDH1 immunoreactivity. Focal elevations of MIB-1 up to 7.5% were noted in 2 cases.

CONCLUSIONS: ONGs are neoplasms with variable degrees of aggressiveness. As more is understood regarding their varied genetic underpinnings, improved pathologic classification and individualized treatment regimens may be achieved. The authors hope that this study helps guide the oculoplastic community toward a multi-institutional, prospective study of ONG genomic sequencing.