Abstract
Purpose: :
To determine whether juvenile astrocytomas WHO grade I have the potential for spontaneous malignant transformation and dissemination. Changes to current intraocular treatment modalities are proposed.
Methods: :
A literature search was performed cross-referencing juvenile pilocytic astrocytoma, pilocytic astrocytoma, astrocytoma grade I, optic glioma, glioma, low-grade gliomas, polar spongioblastoma, gliocytoma embryonale, and malignant transformation, anaplasia or anaplastic change. Bibliographic PubMed and Google searches were performed, and reference ophthalmology and neuropathology textbooks were utilized.
Results: :
A total of 52 purported cases of malignant transformation were found. Twenty two of these tumors, however, did not initially match criteria for astrocytoma WHO grade I and were then excluded. Six other cases were located within an irradiated field and represented anaplasias developing independently of the primary tumor. The remaining 24 malignancies had all been previously irradiated.
Conclusions: :
Visual pathway WHO grade I juvenile astrocytomas do not undergo spontaneous anaplastic transformation. Malignant transformations have been only iatrogenic and demonstrated following radiation therapy. Clinical and histopathological opinions regarding type I astrocytomas as hamartomas are reaffirmed.Surgical excision can thus be indicated to remove intraocular hamartomas such as gliomas. Surgery should be considered only for actively enlarging intraocular hamartomas producing mass effects in an effort to preserve vision and potential enucleation. Previous concerns regarding the effect of disseminating tumor cells via surgery are unwarranted.
Keywords: tumors • astrocyte • vitreoretinal surgery