Pulmonary metastasis of transmissible venereal tumour in a dog: a case report

Résumé

The transmissible venereal tumour (TVT) is one of the most frequent neoplasias in dogs. This tumour has specific characteristics, and it is exclusively of canines. Its transmission occurs through viable neoplastic cell transplantation when in contact with mucosa or unhealthy skin and rarely metastasise. This paper aims to report a rare presentation of pulmonary metastasis of widespread transmissible venereal tumours in a Blue Heeler dog. The patient was cachectic, dyspnoeic, and dehydrated and had multiple skin and pharynx nodulations. The cytology of all cutaneous nodulations showed round vacuolated cells with large eccentric nuclei and loose chromatin, which is compatible with TVT’s microscopic characteristics. Owing to the clinical evolution and reserved prognosis, the patient was euthanized. Necroscopy revealed a mass in the right pulmonary caudal lobe. The mass showed the same histopathologic characteristic of the others: not encapsulated infiltrative neoplastic proliferation of round vacuolated cells. The atypical manifestation of cutaneous metastasis and mainly pulmonary metastasis, in this case, denote the importance of TVT inclusion as a differential in cutaneous neoplasia, even if they show distant organ metastasis. Therefore, it emphasised the importance of cytology and histology in the diagnosis of nodular affections.