Abstract:

Transmissible Venereal Tumor (TVT) is highly contagious round cell tumor and its origin is unknown. In our study, we aimed to evaluate CD3, CD79αcy, vimentin, α-smooth muscle actin, s100 and cytokeratin 5/6 expressions immunohistochemically in order to reveal the cellular characterization of TVT. The material of this study consisted of ten dog tissue sections, six females and four males diagnosed with TVT. Tissue samples from dog were fixed in a 10% buffered formaldehyde solution. After routine tissue procedures follow-up, Hematoxylin & Eosin stain was applied to the sections and investigated under a light microscope. The smear prepared from tumor was examined with the Diff-quick method for cytologically. Immunohistochemical staining was performed on the tissues using the avidin-biotin immune peroxidase complex method. Based on macroscopic, histopathological and cytological findings, we decided that the cases were TVT. All cases were negative for all markers except vimentin expression in round tumoral cells. The negative immunoreactivity of CD3, CD79αcy, α-smooth muscle actin and cytokeratin 5/6 in tumor cells suggests that the origin of the tumor is not lymphocytic, smooth muscle cells or epithelial. Only the option of histiocytic origin remains.

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