Peripheral T-cell lymphoma in the oral cavity of a cow
Guizelini, Carolina de CastroPupin, Rayane ChitolinaBarros, Claudio Severo Lombardo dePavarini, Saulo PetinattiGomes, Danilo Carloto
Background: Squamous cell carcinomas and lymphomas are the most prevalent neoplasms in cattle, the latter usually being attributed to infection by bovine leukemia virus (BLV). Neoplasms of the oral cavity are sporadic in cattle, with but asingle case of lymphoma involving this anatomic site in a bovine reported to date. This paper reports a case of lymphomainvolving the oral cavity of a dairy cow. The clinical and pathological aspects of the tumor are described and discussed.Case: A 39-month-old Holstein-Friesian cow was presented with weight loss and a tumorous growth in the left masseterregion, tearing in the left eye, and mild ipsilateral exophthalmos. Treatment with antibiotics was unsuccessful. The tumorgrowth was 16 x 11 cm, with a soft center and firm periphery, multilobulated, with white intercalated with black and friableareas from which a fetid odor emanated. The cut surface was predominantly white-yellow. A cross-section of the head,caudal to the second molar, revealed a mass infiltrating and almost completely obliterating the left nasal cavity, destroyingthe frontal sinus, the ventral conchae, and the middle and ventral meatus, and compressing the common meatus. The tracheobronchial, mediastinal, and internal iliac lymph nodes were enlarged and masses with similar characteristics to thosein the oral cavity replace their parenchyma. Microscopically, the mass consisted of large neoplastic lymphocytes arrangedin a non-encapsulated and infiltrative mantle and supported by scarce fibrovascular tissue. The cytoplasm of neoplasticcells was scarce and had distinct boundaries; the nuclei were round or oval, the chromatin was finely granulated, and theprominent nucleolus had occasionally multiplied. Nuclear pleomorphism was marked and there were, on average, five mitotic figures per microscopic field of 400x. Similar neoplastic cells obliterated the normal...(AU)
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