Pathologic observations on the canine mammary gland tumors and immunohistochemical study on the origin of chondroid tissue in mammary gland mixed tumors

개 유선종양의 병리학적 관찰 및 유선 혼합종양의 연골기원에 관한 면역조직화학적 연구

Sixteen mammary gland tumors were collected from Seoul National University and Kangwon National University. The average age of the bitches with mammary gland tumor was 10 years. Total 17(60.7%) out of 28 tumor masses observed in 4th and 5th glands. Classification of these tumors according to Hampe and Misdorp were simple adenoma, complex adenoma, benign mixed tumor, papillary adenocarcinoma, solid adenocarcinoma and malignant mixed tumor. Immunohistochemical reaction of the intermediate filaments against normal canine mammary gland showed as followed; anti-cytokeratin 18 was strong and anti-cytokeratin 14 was moderate to the luminal epithelium. Anti-cytokeratin 14 and anti-pancytokeratin to the myoepithelium were showed strong, but anti-vimentin was weak in reactivity. Anti-vimentin to the interstitial cells was represented strong reactivity. The origin of cartilage in mixed tumor of canine mammary gland was studied immunohistochemically with antibodies against intermediate filament. In mammary gland mixed tumors, cartilage tumor tissues were surrounded with the irregularly demarcated three zones composed of adjacent star shaped cells in myxoid areas, proliferative spindle shaped cells and basal located proliferated cells. From basal proliferated cells to star shaped cells, the immunohistochemical reactivity of myoepithelium specific anti-pancytokeratin was decreased gradually and the reactivity of interstitial cell specific anti-vimentin was increased gradually. Based on these immunohistochemical staining patterns, we suggested that the origin of cartilagenous components in canine mammary gland mixed tumor is most likely to the proliferation and metaplsia of myoepithelium.