Tumor venéreo transmissível canino com múltiplas localizações extragenitais
Filgueira, Kilder DantasPeixoto, Gislayne Christianne XavierFonseca, Zuliete Aliona Araújo de SouzaPaiva, Ariana Lopes Correia de
Background: Transmissible venereal tumor (TVT) is a neoplasm which primarily affects the genital mucosa of canines. However, this tumor has been described in several extragenital areas. Although there are no major difficulties to confirm a TVT when present in the genitalia, it can be confused with several conditions, either neoplastic or non-neoplastic, when located beyond the external reproductive organs. The involvement of multiple extragenital locations is poorly reported, which may compromise the tissues involved and hinder the establishment of a diagnostic conclusion. The study aimed to describe a case of multiple and extragenital TVT in dogs. Case: A two year old mongrel dog had a history of swollen nose and ocular abnormalities. The patient underwent physical examination followed by request of nose and eye cytology. The animal was euthanized and sent for autopsy; the material was intended for cytological diagnosis. It was found an increase in volume in the middle third of the nasal region. In the oral cavity, there was a tumor in the caudal third of the hard palate. Neoformations were also detected in the third eyelid. The nasal and eyelid cytological examination was compatible with TVT plasmacytoid pattern. During the necropsy, it was also detected tumors in the nasal cavity, occupying the space of turbinal bones Proliferation occurred even in the palatine bone and pharynx. In the visual system, the tumors did not involve other attachments or eyeball chambers There were no anatomical lesions In other areas. The cytopathology of all tumors presented diagnosis similar to the initial microscopic findings, thus characterizing a framework of multiple extragenital plasmacytoid TVT. Discussion: A study found that the nasal cavity and skin tissue were the locations most affected by the presentation of extragenital TVT. So, there was a similarity to the present case in relation to the shape of the nasal TVT; however, the occurrence in other sites such as the oral cavity and third eyelid is uncommon, although found in the patient reported. The extragenital location may appear regardless to genital lesions. In the examined animal, the placement of the TVT to extragenital areas such as nasal and ocular adnexa was justified by the fact that these regions correspond to anatomical sites exposed to direct physical contact for the acquisition of neoplastic cells, possibly because of the premating behavior of the male toward the bitch that housed the tumor. As an intranasal neoplasia progresses, some signs, such as the swelling of the hard palate, are presented. Thus, in the current study, the proliferation showed in the oral cavity and the pharynx was regarded as an extension of local mechanical nasal cancer. Recent surveys have ranked the TVT as standard plasmocitoyd, linphocitoyd or mixed. It has been hypothesized that all TVTs start as linphocitoyd, become mixed and then plasmocytoid. The latter condition usually suggests the tumor presence for more than eight weeks, often being seen in non genitals. Accordingly, in the present case there was an agreement with the usual standard morfocelular and the extragenital aspect observed. This morphology suggested that the evolution of TVT showed up late. Although TVT is essentially related to the external reproductive organs, one should be alert to its exclusively extragenital presentation. This peculiar location can lead to a delayed diagnosis because of the similarity with affections of another nature.
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