Pathomorphology of canine mammary tumours with special reference to immunophenotyping

Abstract

The present study was under taken to characterize the pathomorphological newlinefeatures and immunophenotypes in fifty one canine mammary tumours during the newlinestudy period from October 2019 to December 2021. Among the breeds, Spitz newlineshowed highest incidence of mammary tumours. The average age of mammary newlinetumour affected dog was 8.7 years. Mammary tumour was observed in both newlinefemale (n=50) and male (n=1) dogs. Intact female dogs (n=44) either whelped or newlinenot were highly prone for mammary tumour development. Radiography revealed newlinemultiple minute nodules in initial stages and poorly demarcated nodules newlineobliterating the entire surface of the lungs in advanced stages of pulmonary newlinemetastases. newlineOut of 51 tumour cases, 56.86 and 43.14 per cent were noticed on right newlineand left mammary chain respectively. Maximum numbers of tumours were newlineencountered in posterior (82.35%) than anterior (17.65%) glands. Single newlinemammary gland tumours were more common (74.51%) than multiple tumours newlineinvolving more than one mammary gland (25.49%). newlineGross examination of tumours showed variation in size and shapes. newlineTumours varied from soft to hard or bony like consistency and either freely newlinemovable or fixed to the underlying skin with or without ulceration. The cut newlinesurface varied from grayish white to reddish brown in colour, nodular to newlineirregularly lobulated appearance with many cystic areas. newlineCytological examination of 45 mammary tumours revealed 86.67 per cent newlinemalignant and 13.33 per cent benign characters. Cytological grading revealed newline35.56, 31.11 and 33.33 per cent were in grade I, II and III respectively. In newlineimmunocytochemistry, out of 23 samples 7 showed mild to intensive newlineimmnuoreactivity for cytokeratin 5/6 in the cytoplasm and 6 showed mild to newlineintensive immunoreactivity for Ki 67 in the nucleus. newlineHistopathology revealed 14 different histological sub types in which 15.68 newlineand 84.32 per cent were benign and malignant tumours respectively. Histological newlinegrading revealed 41.17, 35.29 and 23.52 per cent of tumours were in grade I, II newlineand III respectively.