ANGIOSIS CARCINOMATOSA IN MAMMARY-TUMORS OF THE DOG - FREQUENCY AND COMBINATION WITH PROGNOSTICALLY IMPORTANT FACTORS

Tissue samples from 118 dogs with lesions of the mammary gland and 11 dogs that died of metastasizing mammary tumours were investigated. Ang iosis carcinomatosa was shown immunohistochemically by using the APAAP method and antibodies against Willebrand factor alone and in combinat ion with actin. The results were linked to tumour differentiation, nec rosis, hemorrhages, inflammation, growth, tumour capsule, tumour local isation, age of the animal, tumour size and a follow-up study of 2 yea rs. Immunohistochemically, 36 % of the samples showed invasion in vess els, whereas HE-stained slides revealed invasion in only 23 %. All con trol cases showed invasion of vessels immunohistochemically. Purely so lid growth of the tumour cells showed invasion of vessels in 70 % of c ases, myoepithelial involvement in tumours only in 29 %. Necrosis and hemorrhages led to an increase of vessel invasion. In cases where the capsule was intact, there was invasion of vessels in only two cases. T umours with invasion of vessels were often localised solitarely in the caudal mammary glands. Large samples showed invasion more frequently than smaller ones. Animals with malignant tumours of the mammary gland that died within two years of these or of unknown causes, showed much more vessel invasion than animals that were still alive at the end of the investigation. If animals died of mammary tumours, they showed a higher percentage of lymph- and hemangiosis carcinomatosa in the prima ry tumours.