Differences in indicators of malignancy between luminal epithelial cell type and myoepithelial cell type of simple solid carcinoma in the canine mammary gland.
Routinely diagnosed simple solid carcinoma (SSC) of the canine mammary gland comprises a heterogeneous group of tumors. Seventy-two cases that had been diagnosed as SSC based on hematoxylin and eosin-stained tissue sections were reclassified immunohistochemically on the basis of myoepithelial markers p63 and α-smooth muscle actin, as well as a luminal epithelial marker cytokeratin 8. Only 23 cases (32%) were true SSC, composed only of luminal epithelial cells, whereas 11 cases (15%) were malignant myoepithelioma (MM), composed predominantly of myoepithelial cells, and 38 cases (53%) were biphasic carcinoma (BC), characterized by biphasic proliferation of luminal epithelial and basal/myoepithelial components. As the pathological parameters were compared between the reclassified tumor types, infiltrative potential, vascular/lymphatic invasion, lymph node metastasis, and Ki-67 labeling index were higher in true SSC compared with MM and BC, suggesting that the former may exhibit a poorer prognosis compared with the latter two.
Department of Veterinary Pathology, Nippon Veterinary and Life Science University (NVLU), Tokyo, Japan.
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Yoshimura
Department of Veterinary Pathology, Nippon Veterinary and Life Science University (NVLU), Tokyo, Japan.
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Nakahira
Department of Veterinary Pathology, Nippon Veterinary and Life Science University (NVLU), Tokyo, Japan.
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Kishimoto
Department of Veterinary Pathology, Nippon Veterinary and Life Science University (NVLU), Tokyo, Japan.
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Michishita
Department of Veterinary Pathology, Nippon Veterinary and Life Science University (NVLU), Tokyo, Japan.
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Ohkusu-Tsukada
Department of Veterinary Pathology, Nippon Veterinary and Life Science University (NVLU), Tokyo, Japan kimimasa@nvlu.ac.jp.
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Takahashi
D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000378:metabolism / Q000473:pathology*; D004285:Dogs; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D008207:Lymphatic Metastasis; D015674:Mammary Neoplasms, Animal / Q000378:metabolism / Q000473:pathology*; D009208:Myoepithelioma / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*
D014408:Biomarkers, Tumor
dog; immunohistochemistry; mammary tumor; myoepithelial cell; p63; simple solid carcinoma