RESUMEN
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.
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.