The Biological and Clinical Behaviour of Pilocytic Astrocytomas of the Optic Pathways

Abstract

The clinical and pathological findings in thirty patients with pilocytic astrocytomas of the anterior visual pathways were analysed. Our cases and those in the literature did not show positive correlation between the extent of surgical resection or irradiation or the presence of residual tumour, and the length of survival or degree of residual disability. Most of these tumours may be considered hamartoma-like growths, akin to developmental malformations, among which aggressive behaviour is exceptional. Their inherently benign nature, associated with long periods of dormancy and spontaneous regression, indicate that treatment should be conservative, and that a surprisingly favourable outcome can often be anticipated.

Pilocytic astrocytomas of the optic nerve and their relation to pilocytic astrocytomas elsewhere in the central nervous system

“…Activation of oncogene-induced senescence may provide a potential explanation for the long periods of dormancy and/or spontaneous regression reported in pilocytic astrocytoma. 40 Because this particular pathway can induce senescence through activation of CDKN2A, 41 positivity for CDKN2A may be a surrogate for the activation of oncogene-induced senescence in pilocytic astrocytoma. Indeed, a worse clinical outcome has been reported for pilocytic astrocytoma lacking CDKN2A expression.…”

Optic pathway gliomas: a review

“…65,80 Even patients with progressive disease have good survival rates. 1,8,65 In 2003, Tow et al 80 studied the morbidity and mortality rates in a cohort of OPG patients with and without NF1, both treated and untreated, who were observed for at least 10 years. Most of the patients who were not treated had NF1 and survived, and they had better visual outcomes than their treated counterparts.…”

Spontaneous Regression of Low-Grade Astrocytomas in Childhood

“…Two additional cases suggest spontaneous regressions of juvenile pilocytic astrocytomas of the visual pathways due to tumor absence at autopsy years after a partial resection and a biopsy [1]. Four of the 22 cases had a documented increase in tumor size prior to the regression [4, 5, 6]and 3 had a history suggestive of tumor progression before diagnosis [7, 8, 9].…”

“…The disease course and outcome of pilocytic astrocytomas of the diencephalic region are variable, and survival and disability can be difficult to correlate to the extent of surgery, the use of radiation therapy or the presence of residual tumor [1]. For unknown reasons, some diencephalic tumors may progress after years of dormancy and others regress spontaneously.…”