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Periódicos Brasileiros em Medicina Veterinária e Zootecnia

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  3. Acta Scientiae Veterinariae
  4. Vol. 48 (2020) - Fascículo suppl.1

Cegueira de origem central associado a adenoma de pars intermedia de hipófise em uma égua

Daoualibi, YasminRocha, Juliana FerreiraBraz, NatáliaBrito, Marilene de FariasAlonso, Luciano da SilvaUbiali, Daniel Guimarães

Background: Pituitary pars intermedia (PI) adenoma is a benign adenohypophysis neoplasm, rare in Brazil, which maycompress adjacent structures and lead to dysfunctions of the endocrine organs. The most affected species are equines,particularly aged animals. This neoplastic disease is often associated with Cushing’s syndrome, when the pituitaryadrenocortical axis is affected. However, this neoplasm is seldom associated with clinical blindness. This paper describesa case of pituitary pars intermedia (PI) adenoma which caused blindness in a mare.Case: An emaciated, blind mare that had difficulty finding water and food was referred to “Hospital Veterinário de GrandesAnimais” of “Universidade Federal Rural do Rio de Janeiro”, in Seropédica, state of Rio de Janeiro, Brazil, and later tothe “Setor de Anatomia Patológica” (SAP/UFRRJ) for necropsy. During necropsy it was found that the animal’s pituitarygland consisted of a circumscribed globous mass measuring 3.5x2.5x2.5 cm, symmetrical and well delimited at the sellaturcica. Several organs were collected, fixed in 10% formalin and then processed for histological examination. The brainwas subjected to serial cleavage along the path of the vision organs. All collected tissues were stained with hematoxylinand eosin; the pituitary was stained with Schiff Periodic Acid (PAS) to differentiate neoplastic cells and with Luxol FastBlue to evidence demyelination. Histopathology found that the pars intermedia (PI) was thickened and compressed theneurohypophysis and adenohypophysis. Cells were arranged in a disorganized manner or formed follicles or cysts containing eosinophilic material (colloid), with granules strongly positive after staining with PAS. Proliferated cells werelarge, polyhedral to ovoid, and contained clear basophilic granular material. The nuclei were spherical to ovoid and therewere mild anisocytosis and anisocariasis. Cysts were frequently found in the pars intermedia (PI)...(AU)

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