Heffalumps, jagulars, and cheshire cats. A commentary on cytokeratins and soft tissue sarcomas.

Abstract

Historically, antibodies to cytokeratin intermediate filaments have been models of target specificity. In most diagnostic settings, the utility of these antibodies was unquestioned; reactivity for cytokeratin was dogmatically equated with epithelial differentiation. Recently, however, the diagnostic importance of these antibodies has been challenged, prompted by the demonstration of cytokeratin reactivity in a variety of "nonepithelial" neoplasms. In this review, the evolving literature on this topic is explored, and the practical implications of these findings are discussed.