Cytokeratin and Epithelial Membrane Antigen Expression in Angiosarcomas: An Immunohistochemical Study of 33 Cases

Abstract

Abstract Context.—Expression of epithelial cell markers can occur in mesenchymal tumors and has been reported in angiosarcomas with variable frequency. In these situations, establishing the diagnosis becomes problematic. Objective.—To determine the expression of cytokeratin and epithelial membrane antigen in angiosarcoma. Design.—To address this issue, 33 well-documented cases of angiosarcomas were retrieved from the archival material of Shands Hospital at the University of Florida, Gainesville, and Jackson Memorial Hospital at the University of Miami, Miami, Florida. These cases were all reviewed and studied using a cytokeratin cocktail (CAM 5.2 and AE1/AE3) and epithelial membrane antigen using standard immunohistochemical techniques. All 33 cases had available material for cytokeratin analysis; however, only 20 cases had enough material for epithelial membrane antigen staining. Results.—In the 33 cases studied, the age range of the patients was 2 to 88 years (mean, 63 years). There were 23 (70%) men and 10 (30%) women. One (3%) of 33 was cytokeratin-immunoreactive and 2 (10%) of 20 were epithelial membrane antigen-immunoreactive. Conclusion.—Cytokeratin and epithelial membrane antigen immunoreactivity in angiosarcomas is infrequent but may be encountered. Interpretation of such expression should be done with caution and in conjunction with the characteristic clinical and morphologic features of the tumor as well as the expression of endothelial cell antigens.