Transmissible venereal tumor (TVT) with metastasis to the mammary gland / Tumor venéreo transmissível (TVT) com metástase para a glândula mamária

ABSTRACT

Background: Transmissible venereal tumour (TVT) is a malignancy that in natural conditions develops in the genitalia of the dog. The nature of this transplantable tumor has been extensively studied, but it has not been possible to associate any viral particle to the development and spread of the disease. Coitus is considered the main form of transmission, related to the presentation of the classic TVT in the external genitalia of dogs, but although rare, it can cause metastasis. The aim of this study was to report two cases of genital presentation of this neoplasm, with metastatic lesions in the mammary gland, to contribute to the better understanding of its biological behavior. Cases Two bitches, one mixed breed, with five years old and another, Pit Bull breed, with one year old, were presented with vulvar bleeding for eight months and 15 days, respectively. Lesions were observed in the vulva and inguinal mammary glands. Clinical examination showed, in two patients, a reddish mass located in the vulva. However, nodules of smooth consistency were identified in the right and left inguinal mammary glands of both dogs. With the exception of mammary lesion located in the right inguinal mixed breed bitch whose cytological diagnosis was lipoma, other lesions were diagnosed as TVT, once samples showed hypercellularity with homogeneous population of round cells with eccentric and...