title: Primary primitive neuroectodermal tumors of the retina and ciliary body in dogs.
abstract: We describe the clinical, histological, and immunohistochemical features of primary intraocular primitive neuroectodermal tumors in eight dogs. Four of eight tumors exhibited histological features similar to human retinoblastomas characterized by Flexner-Wintersteiner rosettes, and fleurettes, and demonstrated variable immunoreactivity for retinal markers opsin, S-antigen (S-Ag) and interphotoreceptor retinoid-binding protein (IRBP). All dogs with tumors displaying histological and immunohistochemical features of retinal differentiation were ≤2 years of age. All tumors diagnosed as medulloepitheliomas (n = 4) did not display histological and immunohistochemical features of retinal differentiation and were present in dogs 7 years or older. Age of onset, in conjunction with immunohistochemistry for opsin, S-Ag, and IRBP, is an important aid in the differentiation of primary, primitive neuroectodermal tumors arising within the canine ciliary body, retina, and optic papilla.
authors.affiliation: Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA. Daniel.Regan@colostate.edu
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Regan
authors.forename: Richard R
authors.initials: RR
authors.lastname: Dubielzig
authors.forename: Caroline J
authors.initials: CJ
authors.lastname: Zeiss
authors.forename: Brad
authors.initials: B
authors.lastname: Charles
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Hoy
authors.forename: E J
authors.initials: EJ
authors.lastname: Ehrhart
mesh_terms: D000818:Animals; D002924:Ciliary Body / Q000473:pathology*; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D008297:Male; D018242:Neuroectodermal Tumors, Primitive / Q000662:veterinary*; D019572:Retinal Neoplasms / Q000473:pathology / Q000662:veterinary*; D014604:Uveal Neoplasms / Q000473:pathology / Q000662:veterinary*
keywords: canine; immunohistochemistry; medulloepithelioma; primitive neuroectodermal tumors; retinoblastoma