Non-teratoid ocular medulloepithelioma in an adult horse/Meduloepitelioma ocular nao-teratoide em um equino adulto

• Published in: Ciência rural Vol. 301792365; no. 4; p. 1
• Main Authors: Silva, Mariana Oliveira, Coelho, Leonardo Costa Tavares, Vidal, Adriane Pereira, Teixeira, Cintia Alves, Ribeiro, Gustavo Henrique Siqueira, Melo, Natalia Cristina de, Fantini, Priscila
• Format: Journal Article
• Language: English
• Published: Universidade Federal de Santa Maria 01.04.2021
• ISSN: 0103-8478; 1678-4596
• DOI: 10.1590/0103-8478cr20200001

This is a case of medulloepithelioma in a 14-year-old mixed breed gelding horse, presenting a large abnormal mass of tissue involving the entire extension of the right eye. Ophthalmic examination showed deformation and swelling of the eye. The animal showed signs of pain on palpation of the organ, but the specific examination of the systems did not reveal any other changes. Due to the extension of the apparently neoplastic mass and the discomfort experienced by the animal, transpalpebral enucleation procedure was decided. The excised tissue was sent for histopathological analysis, wherein a neoplastic proliferation of neuroectodermal cells was noted. The neoplasm was poorly delimited, unencapsulated, infiltrative, sustained by moderate fibrovascular stroma, and formed cords and rosettes with cells arranged in palisades around the luminal structures (Flexner-Wintersteiner rosettes), suggestive of medulloepithelioma. The immunohistochemical profile was also performed, confirming the diagnosis. The neoplastic cells were immunolabeled to vimentin, S100 protein (S100), and specific neuro enolase (NSE), but not for pan cytokeratin (AE1AE3), glial fibrillary acidic protein (GFAP), and cytokeratin 8/18 (CK8/18). Five months postoperatively, the animal was healthy, without any relapse or evidence of metastasis. Key words: ocular neoplasia, tumor, histopathology Esse e um caso de meduloepitelioma em um equino sem raca definida, castrado, de 14 anos de idade, que chegou ao atendimento apresentando grande massa de tecido envolvendo toda a extensao do olho direito. No exame oftalmico, foi observada deformaqao e aumento de volume ocular. O animal manifestou sinais de dor na palpagao do orgao, mas o exame especifico dos sistemas nao revelou demais alteragoes. Devido a extensao da massa aparentemente neopldsica e o desconforto experimentado pelo equino foi decidida a realizagao da enucleagao transpalpebral. O tecido excisado foi enviado para exame histopatologico, no qual observou-se proliferacao neopldsica de celulas neuroectodermicas, de forma mal delimitada, nao encapsulada, infiltrativa, sustentada por estroma fibrovascular moderado, e formacao de cordoes e rosetas, com celulas dispostas em paligadas ao redor de estruturas luminais (rosetas de Flexner-Wintersteiner), sugestivo de meduloepitelioma. O perfil imunohistoquimico tambem foi realizado, confirmando o diagnostico. As celulas neoplasicas for am imunomarcadas para vimentina, proteina S100 (S100) e neuro enolase especifica (NSE), mas nao para pan citoqueratina (AE1AE3), proteina glial fibrilar acida (GFAP) e citoqueratina 8/18 (CK8 /18). Apos cinco meses da realizagao do procedimento cirurgico o animal apresentava-se saudavel, sem recidiva ou evidencia de metdstase. Palavras-chave: neoplasia ocular, tumor, histopatologia.