Visual pathway glioma: an erratic tumour with therapeutic dilemmas

Abstract

Objective-Our experience in children with visual pathway glioma (VPG) was reviewed to delineate its clinical characteristics. Design-The charts and imaging studies of 21 children with VPG who were followed up in our centre during the last 12 years were reviewed and summarised. Results-VPG accounted for 13.1% of all brain tumours treated during this period. Sixty two per cent of the children with VPG had neurofibromatosis type 1 (NF-1). Among these, more than 60% were detected as part of routine work up. In some cases decreasing visual function preceded the appearance of the VPG on imaging studies. Tumour growth rate was markedly unpredictable. All treatment modalities employed led to tumour shrinkage and stabilisation for a variable period, but none was successful in totally eradicating the tumour. Complications were less severe after chemotherapy compared with radiotherapy. Three children died, none with NF-1, with a globular hypothalamic/chiasmatic tumour and accompanying electrolyte abnormalities. Conclusions-NF-1 is a favourable prognostic marker for VPG. Whenever possible a period of observation is necessary before treatment is initiated, during which time tumour size and visual function should be closely followed up; an untoward change in either of these is an indication for the start of treatment, preferably chemotherapy first. The combination of a globular hypothalamic/chiasmatic glioma and electrolyte abnormalities in a child without NF-1 are related to a poor prognosis.

Optic Pathway Hypothalamic Gliomas in Children under Three Years of Age: The Role of Chemotherapy

“…Patients older than 2 years present better prognosis than those younger than 2 years [23]. Furthermore, the majority of children diagnosed with OPHG under 2 years of age do not have NF1, and these children with NF have a more indolent evolution or nonevolution of disease [5, 10, 23, 24]. Other factors for a poor prognosis include tumor location.…”

“…The natural history and behavior of OPHGs are often unpredictable. The literature reports cases of spontaneous regression of tumor [4, 5]as well as progression, which can lead to visual loss, neurological deficits, or death in up to 20–30% of patients [6]. However, more than 50% of OPHGs remain stable without intervention.…”

Optical coherence tomography in the evaluation of neurofibromatosis type-1 subjects with optic pathway gliomas

“…5 The natural history of NF1-associated OPGs is unpredictable. 2,6,7 Generally most tumors present by age 6 years, after which the appearance of symptomatic OPGs and progression of known OPGs requiring therapy is uncommon. [8][9][10] Most patients with NF have stable or even normal visual acuity, but some can experience slow progressive vision loss, and a few develop sudden and profound vision loss.…”

Spontaneous Regression of Low-Grade Astrocytomas in Childhood

“…Only 1 out of 22 tumors in the literature resolved completely over time [12]. One tumor progressed after a period of regression and necessitated chemotherapy [15]. Many reports were published shortly after the regression and therefore did not include follow-up.…”