Hazal ÖZTÜRK (1), Evrim EGEDEN (2), Gülbin ŞENNAZLI (1)
1. Veterinary Faculty of Istanbul University, Department of Veterinary Pathology, Avcılar, İstanbul
2. Ada Veterinary Policlinic, Sulun Street No: 14 1. Levent 34330 Besiktas / Istanbul
Introduction
Canine transmissible venereal tumor (TVT) is a tumoral disease which begins in the genital area as a contagious disease and spreads to other parts of the body and can be observed in the skin and as distant metastasis and its the cellular origin is unknown.
Material & Method
12 year old, mixed breed, male dog was brought to the clinic with complaints of seizure, cachexia, loss of appetite and purulent skin eruption. In clinical examination, generalized lymphodenopathy, paleness in mucous membranes and in abdominal ultrasound examination multiple nodular foci in the spleen were observed. Blood tests revealed pancytopenia, hyperglobulinemia and hypoalbuminemia. Dog was tested serologically for Ehrlichiosis (SNAP4xPlus) and Leishmaniasis (SNAP-Leischmania). Cytologic smears were prepared via fine needle aspiration from the spleen and the skin. Later, under anesthesia, punch biopsy samples were obtained from the skin and histopathologically examined. Biopsy samples were fixed in a 10% formaldehyde buffered solution for 24 hours. Then samples were embedded in paraffin blocks and 3-4 μm width sections stained in hematoxylin and eosin dye were examined under light microscope.
Findings
Serological test results were positive for Ehrlichiosis and negative for Leishmaniasis.
Skin Scraping
Demodex was discovered in the skin scrapings obtained from various parts of the skin.
Macroscopy
Multiple randomly distributed multinodular masses with ulcerated surfaces ranging between 0,3-1 cm in diameter on the back of the neck and back area were observed. Spleen USG: Multiple nodular hyperechoic foci were observed.
Cytology
Skin: Cytology samples prepared from skin lesions showed uniformly round, neoplastic cells with high cellularity and basophilic cytoplasm as multiple same sized cells containing intracytoplasmic vacuoles. Cell nuclei showed mononuclear, eccentric distributed granular, chromatine concentration.
Spleen: small number of plasma cells and neopastic cells which have the same morphological characteristics were observed.
Histopathology
Ulceration infiltrated in the epidermis, partially uniform, eosinophilic, round neoplastic cells with large nuclei extending from dermis to subdermis were observed. Cells had slight granular cytoplasm characterized by irregular borders, significant anisocytosis and anisokaryosis. High mitotic activity and significant hyperchromasia in some cells were observed.
Discussion and Conclusion
In this case report, the patient was diagnosed with TVT as a result of cytological and histopathological examination on masses on skin and spleen metastasis. The highest number of TVT findings were on the skin were on the neck, back, breast and extremities. Although distant metastasis is rare to visceral tissues, reported cases exist. As we have also mentioned in our report, the fact that Ehrlichiosis, Leishmaniasis and infections related to Demodex cause immunosuppression which play a role in the emergence of this disease is also reported in other studies. Patient was administered vincristine (0,5 mg/m2) once a week for 6 weeks, doxycycline (10 mg/kg) every 12 hours for 30 days, doramectin (200 mcg/kg) once a week for 6 weeks. After the treatment, skin and spleen lesions related to TVT completely regressed and the overall health of the patient improved.
