Canine ocular gliomas: a retrospective study.
OBJECTIVE
The purpose of this paper is to classify glial tumors observed in the canine retina and optic nerve, describe the histopathological features and provide prognostic information on these neoplasms.


METHODS
The database of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was searched to collect canine glioma cases. Clinical and follow-up information was gathered from submission forms and an extensive follow-up survey. Slides were reviewed to describe the histopathological characteristics of the neoplasm and classify them. Immunohistochemistry for Glial Fibrillary Acidic Protein (GFAP) was performed in all cases.


RESULTS
18 canine glioma cases were found in the COPLOW database. There was no breed or gender predilection. The mean age was 9.33 +/- 3.67 years. Follow-up information was available for 12 dogs, 8 of which were dead at the time of most recent contact, with a survival time ranging from 0 days (globes received after euthanasia) up to 20 months post-enucleation. In 6 of the 8 dogs that had died during this stud), tumor extended to the margin where the optic nerve had been sectioned. Light microscopic examination of the optic nerve of the affected eyes of four dogs that were still alive during this study revealed no tumor at this surgical margin. One neoplasm was classified as low-grade astrocytoma, 5 tumors as medium-grade astrocytoma, 11 tumors as high grade-astrocytoma and 1 tumor as oligodendroglioma. GFAP was positive in all but two tumors.


CONCLUSIONS
Retinal and optic nerve gliomas may be considered as differential diagnoses of intraocular and orbital masses. The metastatic potential appears to be low, but ascending invasion into the ventral aspect of the brain is possible.
Naranjo
Carolina
C
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Wisconsin, USA.
Schobert
Charles
C
Dubielzig
Richard
R
D000818:Animals; D001932:Brain Neoplasms / Q000556:secondary; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000401:mortality / Q000473:pathology*; D004285:Dogs; D015353:Eye Enucleation / Q000662:veterinary; D005134:Eye Neoplasms / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000276:immunology; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D009361:Neoplasm Invasiveness; D020339:Optic Nerve Glioma / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D011379:Prognosis; D019572:Retinal Neoplasms / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D012175:Retinoblastoma / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D012189:Retrospective Studies; D012307:Risk Factors
D005904:Glial Fibrillary Acidic Protein