Histopathological and immunohistochemical characteristics of malignant adenomyoepithelioma in a cat: case report

ABSTRACT The malignant adenomyoepithelioma is a rare mammary tumor in women and uncommon in cats with only one report in this species. In this case report, the histopathological and immunohistochemical characteristics of six cases of malignant adenomyopithelioma in the feline mammary gland are described. Microscopic evaluation of tumors showed dense cellular neoplastic proliferation, composed of malignant myoepithelial and epithelial cells, formed by varied arrangements and presenting papillary, tubular and solid nest proliferation. Immunohistochemistry was performed for markers Ki67, Cox-2, RE, RP, p63 and HER-2. All cases were positive for p63, confirming the myoepithelial nature of neoplastic cells. The diagnosis of malignant adenomyopithelioma was made possible through the association between histopathological characteristics and immunohistochemical results.

摘要：恶性腺肌上皮瘤（malignant adenomyoepithelioma）是女性罕见的乳腺肿瘤，在猫中亦极为少见，目前仅见1例相关报道。本病例报告描述了6例猫乳腺恶性腺肌上皮瘤的组织病理学与免疫组织化学特征。显微镜下观察可见肿瘤组织呈现致密的肿瘤性细胞增殖，由恶性肌上皮细胞与上皮细胞构成，排列形式多样，呈现乳头状、管状及实体巢状增殖模式。本次研究针对Ki67、Cox-2、RE、RP、p63及HER-2等标记物开展免疫组织化学检测，结果显示所有病例均呈p63阳性，证实了肿瘤细胞的肌上皮表型。通过结合组织病理学特征与免疫组织化学检测结果，即可确诊为恶性腺肌上皮瘤。