Este relato de caso descreve os achados clínicos, histopatológicos e imuno-histoquímicos em dois cães com mielopatia associada à metástase de carcinoma de tireoide. Microscopicamente, ambos os neoplasmas primários eram caracterizados por células poligonais arranjadas em folículos (ocasionalmente preenchidos por material eosinofílico semelhante a coloide) ou em folhetos. As células neoplásicas tinham moderado citoplasma eosinofílico e moderada anisocitose e anisocariose. Adicionalmente, as células neoplásicas foram positivas para tireoglobulina, confirmando a origem folicular dos tumores em ambos os cães. Essa é uma apresentação incomum dessa condição patológica.

This case report describes the clinical, histopathological and immunohistochemical findings in two dogs with myelopathy associated with metastasis of follicular-compact thyroid carcinoma. Microscopically, both primary neoplasms were characterized by polygonal cells arranged in follicles (occasionally filled with eosinophilic colloid-like material) or in sheets. The neoplastic cells had a moderately eosinophilic cytoplasm and there was moderate anisokaryosis and anisocytosis. Additionally, the neoplastic cells were positive for thyroglobulin on immunohistochemistry, confirming the follicular origin of both tumors. This is a very uncommon presentation of this pathological condition.

Resumo: Com o objetivo de determinar a epidemiologia e as características morfológicas, incluindo a localização anatômica, das lesões extrarrenais de uremia, bem como determinar as principais lesões do sistema urinário associadas à ocorrência de uremia, foram revisados os protocolos de necropsias de cães realizadas no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria de janeiro de 1996 a dezembro de 2012 (17 anos). Nesse período foram necropsiados 4.201 cães, sendo que 161 (3,8%) apresentaram lesões extrarrenais de uremia. Em 134 cães (83,2%) foram descritos sinais clínicos associados à uremia. As lesões extrarrenais mais frequentes, em ordem decrescente, foram: gastrite ulcerativa e hemorrágica (56,5%), mineralização de tecidos moles (55,9%), edema pulmonar (47,2%), estomatite e/ou glossite ulcerativa (30,4%), endocardite/trombose atrial e aórtica (28,6%), hiperplasia das paratireoides (9,3%), osteodistrofia fibrosa (8,1%), anemia (6,2%), laringite ulcerativa (5%), enterite ulcerativa/hemorrágica (3,7%), esofagite fibrinonecrótica (1,9%) e pericardite fibrinosa (1.9%). Na maioria dos casos as lesões extrarrenais de uremia foram decorrentes de azotemia prolongada por lesões renais graves, sendo as mais prevalentes a nefrite intersticial e a glomerulonefrite.

Abstract: The aim of this study was to determine the epidemiology and the morphological characteristics (including the anatomic localization) of the extrarenal uremic lesions, as well as to describe the main lesions of the urinary system associated with the occurrence of uremia, through analysis of the protocols of necropsies performed in dogs from January 1996 to December 2012 (17 years) at the Laboratório de Patologia Veterinária of the Universidade Federal de Santa Maria. A total of 4,201 dogs were necropsied and 161 (3.8%) had extrarenal uremic lesions. In 134 dogs (83.2%) clinical signs associated with uremia were reported. The extrarenal lesions more often observed, in descending order of prevalence, were ulcerative and hemorrhagic gastritis (56.5%), soft-tissue mineralization (55.9%), pulmonary edema (47.2%), ulcerative stomatitis and/or glossitis (30.4%), endocarditis/atrial and aortic thrombosis (28.6%), parathyroid hyperplasia (9.3%), fibrous osteodystrophy (8.1%), anemia (6.2%), ulcerative laryngitis (5%), ulcerative and hemorrhagic enteritis (3.7%), fibrinonecrotic esophagitis (1.9%), and fibrinous pericarditis (1.9%). In most of the cases, the extrarenal lesions of uremia were due to prolonged azotemia secondary to severe renal lesions, such as interstitial nephritis and glomerulonephritis (the most prevalent ones).