To evaluate the expression levels of Cyclin D1 in breast papillomas and papillary carcinomas, and to analyze the types of cells that co-express Cyclin D1 with Cytokeratin 5/6 (CK 5/6) or with Cytokeratin 8/18(CK 8/18). The gene discussed is CCND1; the disease is thyroid gland papillary carcinoma.