Canine Head Tumours Evaluated by CT-scan A retrospective study (20-11-2007 till 19-4-2013)

Abstract

Many tumours can manifest on the canine head. These tumours come from different origins and have different behaviours. Even the same tumour can behave differently on different sites (for example squamous cell carcinomas). The goal of this study was to give an insight in the type of tumours presented at the University Clinic of the Faculty of Veterinary Medicine of Utrecht University and their prevalence and behaviour. By using the patients databases of the division of diagnostic imaging and the university clinic a list was made of patients who were presented for CT-scan of the head to evaluate a tumour of the head. From these patients an overview was made containing information about the patient (patients number, gender, age, breed and breed group), the tumour (final diagnosis, histological type, localization and the presence of osteolysis) and whether or not a scan (radiograph or CT-scan) of the thorax was made and the outcome of this scan(whether or not there were any lung metastases found). 358 patients were presented for a CT-scan of the head for evaluation of a tumour. Fifty-six (15.64%) patients were crossbreeds and 305 (84.36%) were pure breeds. Thirty-four different tumours were found in 242 patients. The most common tumours were squamous cell carcinoma (58; 16.20%), malignant melanoma (31; 8.66%), adenocarcinoma (24; 6.70%), sarcoma (20; 5.59%), fibrosarcoma (16; 4.47%), carcinoma (15; 4.19%), acanthomatous ameloblastoma (15; 3.91%) and osteosarcoma (9; 2.51%). In 182 cases a CT-scan (160) or radiograph (20) of the thorax was performed. In 18.1% (33) of the cases lung metastases were found. Only the breed groups seemed to have a significant influence (P<0.0005) on the type of tumour. The other variables did not have a significant influence on the type of tumour or the n was too small for statistical analysis. Age (young versus old) seems to have a significant (P=0.017) influence on sarcoma. Location seems to have a significant (P=0.008) influence on osteosarcoma. In case of malignant melanoma the age (P<0.0005) and location (P=0.009) seem to be of influence. No significant effects of tumour, histological type or localization were seen on the presence of lung metastases. Although it seems that melanocytic tumours were the most malignant histological type and no lung metastases were seen in tumours located at the ear, sarcomas and acanthomatous ameloblastoma. Localization and histological type seem to have a significant influence on the occurrence of osteolysis. Tumours in the oral space most frequently cause osteolysis. Between the histological types this were the epithelial tumours. In conclusion this research gives an overview of the tumours of the canine head that were presented at the University Clinic and their behaviour as to cause osteolysis and metastatic disease to the lungs.