title: Orbital (retrobulbar) meningioma in a Simmental cow.
abstract: A 12-year-old Simmental cow was presented with a moderately firm irregular whitish mass of approximately 5 cm in diameter, occupying the right orbit. Microscopically, a poorly differentiated neoplasm was observed. The immunohistochemical panel included cytokeratins, vimentin, epithelial membrane antigen, Factor VIII, CD34, Mart-1, Melan A, smooth muscle actin, desmin, chromogranin, neuron-specific enolase, S-100 protein, and MIB-1. The neoplasm was negative for all of them, with the exception of vimentin and S-100 protein. Transmission electron microscopy revealed abundant desmosomes. These findings support the diagnosis of orbital (retrobulbar) meningioma.
authors.affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília, DF, Brazil.
authors.forename: J L
authors.initials: JL
authors.lastname: Reis
authors.forename: C T
authors.initials: CT
authors.lastname: Kanamura
authors.forename: G M
authors.initials: GM
authors.lastname: Machado
authors.forename: R O
authors.initials: RO
authors.lastname: França
authors.forename: J R J
authors.initials: JR
authors.lastname: Borges
authors.forename: R L
authors.initials: RL
authors.lastname: Santos
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D008579:Meningioma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D009918:Orbital Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*