title: Ocular glioneuroma with medulloepitheliomatous differentiation in a goldfish (Carassius auratus).
abstract: An intraocular mass in the left eye causing chronic severe exophthalmia in an adult female goldfish (Carassius auratus) is described. The fish shared an aquarium with another goldfish found dead with gross and microscopic lesions consistent with mycobacteriosis. Histological examination of the left eye, histochemical (periodic acid-Schiff [PAS], Alcian blue, Ziehl-Neelsen) and immunohistochemical tests (glial fibrillary acidic protein, human neuronal protein, vimentin, and cytokeratin AE1/AE3) were carried out on the intraocular mass. Neoplastic cells forming an unencapsulated highly cellular proliferation partially covered by an intact corneal epithelium were stained with Alcian blue, which demonstrated an abundant hyaluronic acid-rich extracellular matrix. Multifocally, there were cyst-like dilatations bordered by neuroepithelial cells, which were PAS-positive. The complex neoplastic proliferation was composed of glial-like cells, neuronal-like cells (immunoreactive to glial fibrillary acidic protein and human neuronal protein, respectively) and neuroepithelium, which suggested a retinal origin.
authors.affiliation: 1Luciana Mandrioli, Service of Anatomic Pathology, Department of Veterinary Medical Sciences, Via Tolara di Sopra 50, Ozzano Emilia, Bologna, Italy. luciana.mandrioli@unibo.it.
authors.forename: Luciana
authors.initials: L
authors.lastname: Mandrioli
authors.forename: Rubina
authors.initials: R
authors.lastname: Sirri
authors.forename: Andrea
authors.initials: A
authors.lastname: Gustinelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Quaglio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sarli
authors.forename: Roberto
authors.initials: R
authors.lastname: Chiocchetti
mesh_terms: D000818:Animals; D002277:Carcinoma / Q000473:pathology / Q000662:veterinary*; D002454:Cell Differentiation / Q000502:physiology; D005134:Eye Neoplasms / Q000473:pathology / Q000662:veterinary*; D017809:Fatal Outcome; D005260:Female; D005393:Fish Diseases / Q000473:pathology*; D006054:Goldfish; D007150:Immunohistochemistry / Q000662:veterinary; D009463:Neuroma / Q000473:pathology / Q000662:veterinary*
keywords: Carassius auratus; glioneuroma; goldfish; histochemistry; histology; immunohistochemical staining; medulloepithelioma; tumors