Computer tomographic imaging in 4 dogs with primary nasal canine transmissible venereal tumor and differing cellular phenotype

Abstract

Primary nasal canine transmissible venereal tumor (CTVT) without genital affection is uncommon. The aim of this report was to describe the primary nasal CTVT findings and CT staging in 4 dogs with different cytological phenotypes. Three male dogs and 1 bitch were evaluated for their chronic histories of sneezing, snoring, mucopurulent nasal discharge and nasal deformation. Cytological examination of nasal secretions suggested CTVT, confirmed by histopathological examination and LINE-1/c-myc. Males had the plasmacytoid phenotype of CTVT, and the bitch had the lymphocytoid phenotype. CTVT were staged based on the CT findings using modified Adams staging system. The bitch was classified as stage 1, 2 males were classified as stage 3 and 1 male as stage 4. All dogs had a complete tumoral remission after chemotherapy. Plasmacytoid phenotype was identified in cases with most important damage of the nasal cavity. However, the cytological type did not affect the response to chemotherapy.

Keywords: CTVT; cytology; dogs; nasal tumor.

Figure 1

Nasal cytology smears showing the plasmacytoid CTVT phenotype with ovoid cells, abundant cytoplasm, several vacuoles, and an eccentrically located nucleus (A). Nasal cytology smears showing the lymphocytoid CTVT phenotype with round cells, finely granular cytoplasm, few clear vacuoles, nuclei centrally located and a coarse chromatin pattern and 1–2 distinct nucleoli (B). Diff‐Quick stain, Scale Bar = 20 μm

Figure 2

Transverse computed tomographic images of the nasal cavities and maxillary recesses of four dogs with nasal CTVT. CT showed an irregular, soft‐tissue mass occupying nasal turbinates and paranasal bones destruction (A, B, D). The soft tissue attenuation was between 80 and 120 HU

Figure 3

Nasal primary CTVT histopathology showing the multinodular compact proliferation of pleomorphic, round cells separated by a delicate fibrovascular stroma. The cells have a large prominent nucleus and a moderate amount of cytoplasm, large ovoid nuclei with 1–2 prominent nucleoli and multiple mitotic figures. Hematoxylin and eosin stain, Scale Bar = 30 μm

Figure 4

Transverse computed tomographic images of the nasal cavities and maxillary recesses of four dogs with nasal CTVT after completing chemotherapy. CT showed turbinate and paranasal bones destruction with fluid attenuation associated with mucus accumulation (A, B, D). The soft tissue mass completely disappeared without evidence of bone destruction (C)