Pilocytic Astrocytoma of the Optic Nerve with Hemorrhage and Extreme Cystic Degeneration

Pilomyxoid Astrocytoma: Expanding the Imaging Spectrum

“…[18][19][20][21][22][23][24][25][26][27][28] Until recently the rate of hemorrhage in PA was estimated at Ͻ1%. However, a recent retrospective series of 134 patients with a tissue diagnosis of PA found an 8% spontaneous hem- orrhage rate, much higher than that previously reported.…”

Rate of spontaneous hemorrhage in histologically proven cases of pilocytic astrocytoma

“…In fact, very few cases have been reported in the literature, and to our knowledge there have been no studies reporting on the rate of hemorrhage for World Health Organization Grade I astrocytomas. [1][2][3][4][5][9][10][11][13][14][15] The purpose of this study was to review histologically proven cases of PAs and determine the number of patients who presented with imaging-documented hemorrhage.…”

Symptomatic Hemorrhage Associated With Recurrent Pilocytic Astrocytoma With Granulation Tissue-Case Report-

“…2,7,8,12,13,15-19,22-25, 32,33,36,37) Such hemorrhage was observed in the intratumoral, intracerebral, intracerebellar, ventricular, and subarachnoid spaces, and the outcome was affected more by the extent of bleeding than the location of the tumor or hematoma. 2,7,8,12,13,[15][16][17][18][19][22][23][24][25]32,33,36,37) High-grade gliomas and metastatic lesions bleed from structural abnormalities of the tumor vessels, tumor invasion of vessel walls, and necrosis. 18) Although the mechanism that results in hemorrhages in pilocytic astrocytomas is unclear, the bleeding may originate from abnormal vessels with thin walls, endothelial proliferation, retiform capillaries, encased aneurysm, stromal degeneration, stretched brain, infarction, coexisting vascular malformations, or congestive vessels.…”