breast cancer 12-P63 Expression in Breast Cancer.ppt

P63 Expression in Breast Cancer A Highly Sensitive and Specific Marker of Metaplastic Carcinoma Meryem M. Koker, MD and Celina G. Kleer, MD (Am J Surg Pathol 2004；28：1506 – 1512) Abstract p63, a member of the p53 gene family, is involved in cellular differentiation and is expressed in the nuclei of myoepithelial cells of normal breast. In this study, we determined p63 expression in a large number of breast carcinoma, including metaplastic carcinoma, and in Phyllodes tumors and sarcoma. 189 invasive breast carcinomas, including 15 metaplastic carcinomas, as well as 10 Phyllodes tumors, and 5 pure sarcoma of the breast for pattern and intensity of p63 staining using an anti-p63 antibody (clone 4A4, Neomarkers) p63 is strongly expressed in 13 of 15 metaplastic carcinoma (86.7%). p63 is positive in all the metaplastic carcinoma with spindle cell and/or squamous differentiation (12 od 12). Only 1 of 174 (0.6%) nonmetaplastic invasive carcinomas was positive for p63. All Phyllodes tumors and sarcomas were consistently negative for p63 expression. The sensitivity and specificity of p63 as a diagnostic marker for metaplastic carcinoma was 86.7% and 99.4% p63 as part of the diagnostic workup of challenging spindle cell tumors of the breast as a highly specific marker for metaplastic carcinomas. 前言： Metaplastic carcinoma of the breast (MCB) are a rare and heterogeneous group of tumors defined by a cellular component with an appearance other then epithelial and glandular. These tumors may be biphasic and contain glandular elements mixed with a nonglandular component. The majority of metaplastic carcinoma exhibit spindle cell with or without squamous differentiation. The spindle cell component of metaplsic carcinoma from low-grade “fibromatosis-like” lesions to high grade spindle cell malignancies resembling fibrosarcoma or malignant fibrous histiocytoma. The diagnosis of metaplastic carcinoma is straightforward when a direct transition from glandular epithelial to