PMC3994684_01
Comparison of preoperative and postoperative MRI scans. (a) Preoperative T1-weighted contrast enhanced axial MRI showing brightly enhancing right optic nerve lesion (Red arrow). (b) Postoperative T1-weighted contrast enhanced axial MRI showing gross total excision of tumor. (c) Preoperative FLAIR MRI shows hyperintensity of bilateral optic tracts (Red arrows). (d) FLAIR signal extends into the right lateral geniculate nucleus (Red arrow). (e) Postoperative FLAIR MRI shows the optic tract hyperintensity is resolved
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Magnetic resonance imaging (MRI) scans of the brain with and without gadolinium revealed an avidly enhancing mass of the right optic nerve distal to the optic chiasm involving the cisternal, canalicular, and orbital components of the nerve measuring 1.2 cm in maximal diameter [Figure 1a]. In addition, increased FLAIR signal was noted in the optic tracts bilaterally, which was not observed in the prior study [Figure 1c], suggesting the diagnosis of an infiltrating optic nerve glioma.
Right anterior skull base exposure (a) Right anterior skull base exposure showing reddish optic nerve tumor. (b) Dura propria incised over optic nerve tumor. (c) Optic nerve sectioned distal to the chiasm (Blue arrow). Black arrow denotes right internal carotid artery. Green arrow denotes the chiasm
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The ophthalmic artery was then identified, coagulated and cut [Figure 2].
Histopathology of hemangioblastoma involving the optic nerve orbital and intracraneal portions. (a) Low power view of cross sections of central portion of the optic nerve with tumor. Notice the vascularized tumor in the center and residual optic nerve tissue (*). The edges show cautery artifact (arrows). H and E, x1 original magnification. (b) Higher magnification showing residual nerve fibers (*). Notice the vascular nature of the tumor and the foamy cells of the stroma. H and E, x10 original magnification. (c) PAS stain highlights the basement membrane of the vessels and absence of glycogen or mucin in the vacuoles of the stromal cells. Periodic Acid Schiff (PAS), x20 original magnification. (d) Close up of the two components of the tumor, the vessels and the vacuolated stromal cells. H and E, x100 original magnification
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