Study on histopathological subtypes and grading of canine mammary tumours
Christy Margrat Joy, I. S. Sajitha , S. S. Devi , B. Dhanush Krishna and Sudheesh S. Nair
The incidence of mammary neoplasms is more in dogs when compared to other animals. Mammary neoplasms are among the most prevalent type of tumours in bitches, followed by skin tumours. Canine mammary tumour (CMT) and human breast cancer (HBC) have clinical and molecular similarities, making CMT a good model to study HBC. A study was conducted on 25 cases of CMT in bitches which were presented during a period from March 2019 to March 2020 to University Veterinary Hospitals at Mannuthy and Kokkalai. Tumours were histologically classified basically into carcinoma, sarcoma, carcinosarcoma, benign tumour and further its subtypes were identified. Out of total 25 CMTs, only one case was identified as benign, while all the other cases were found to be malignant. Modified Elston and Ellis grading method was used for histological malignancy grading of CMT. Histological malignancy grading done in 23 cases revealed grade I (30.43 per cent), grade II (60.87 per cent) and grade III (8.7 per cent) malignancy. Sixty-five per cent of simple carcinomas, which included ductal carcinoma, tubulo-papillary carcinoma, solid carcinoma, comedocarcinoma and cribriform carcinoma, were either grade II or III, while all the mixed tumours were grade II. The present study revealed that histological malignancy grading could be used as a tool for predicting prognosis of CMT.
Keywords: Canine mammary tumour, histological classification, grading