Radiographic, Computed Tomographic, and Cellular Phenotypic Features of Primary Nasal Transmissible Venereal Tumors in Four Dogs

Abstract

The primary nasal canine transmissible venereal tumor (CTVT) is a rare disease that develops by the allografted transmission of neoplastic cells in the nasal cavity. The disease is uncommonly reported in free-roaming dogs, with the social behavior of excessive licking and vigorously sniffing the affected parts of the other dogs in an endemic population. Post-chemotherapeutic computed tomography (CT) scan features and correlation of vincristine sulfate with cellular phenotypes have been scarcely reported in previously available primary nasal CTVT studies. This study describes the radiographic, computed tomographic, and cellular phenotypic features in four dogs affected with stage-4 intranasal CTVTs. The post-chemotherapeutic features of the nasal cavity in fully recovered cases are also highlighted. All data were analyzed retrospectively. All four dogs had stage 4 modified Adam’s staging for nasal tumors due to the complete or partial lysis of the cribriform plate and lymphocytoid plasmacytoid (mixed) phenotype of the neoplastic cells based on the cellularity of cytological samples. All four dogs responded well to five cycles of vincristine sulfate and recovered completely. Two out of four dogs have follow-up scanning after chemotherapy. Based on the present study results, vincristine sulfate is still an effective monotherapy to achieve full recovery, although the number of cycles can vary, possibly depending on the expressed phenotype. Permanent loss of nasal turbinates is the sequelae of therapeutic chemotherapy. Prognosis is not correlated to the staging system but seems good with vincristine sulfate in mixed phenotype cases.