Expression of D2‐40 in adjunct diagnosis of papillary thyroid carcinoma

The clinical pathologic criteria for nuclear features of papillary thyroid carcinoma are subjective and sometimes cannot distinguish carcinoma from adenomatous goiter and follicular neoplasms. No single antibody has demonstrated high sensitivity or specificity in making these distinctions. Using quantitative analysis of immunohistochemical staining with D2-40, a recently available monoclonal antibody used as a lymphatic endothelial marker, we examined 72 cases of papillary carcinoma. Controls included 36 follicular adenomas, 36 follicular carcinomas, and 20 adenomatous goiters with papillary hyperplasia. Cytoplasmic D2-40 immunoreactivity was present in 60 of 72 papillary carcinomas, 2 cases of follicular adenoma and 2 cases of follicular carcinoma, whereas no adenomatous goiter or normal thyroid glands contained positive epithelial cells. Overexpression of D2-40 in papillary thyroid carcinomas thus has potential diagnostic utility in differentiating these tumors from their potential histologic mimics.