Metástase múltipla de carcinoma de células escamosas ocular em bovino: dois casos

Abstract

Among the various tumor affecting cattle, ocular squamous cell carcinoma is the most common in this species, causing considerable losses to farms. Several factors involved in the pathogenesis, but constant exposure to ultraviolet light and the reduced amount of pigmentation around the eyes are related to higher prevalence. The tumor occurs mainly in the lower eyelid, the nictitating membrane and corneoescleral junction. Two unusual cases of ocular squamous cell carcinoma that resulted in multiple metastases to regional lymph node, salivary gland and lung in cows created in southwest Goiás. Histopathology exams of all cases revealed hypercellular proliferation of neoplastic keratinocytes blocks. Cells had broad and eosinophilic cytoplasm, rounded nuclei and central basophilic, with loose chromatin and one to two large and prominent nucleoli. There was marked anisocytosis and anisokaryosis seven to ten mitoses in ten 400X fields. Prolonged exposure to sunlight and depigmentation of the affected primary tissues were considered important predisposing factors.