In addition to the known immunophenotypic features of the disease, we identified the expression of FLI (in three out of three cases) and WT-1 (in one of three cases), which are endothelial and mesothelial markers, and are findings to be cognizant of to avoid misdiagnosis as angiosarcoma or mesothelioma, respectively. The gene discussed is WT1; the disease is mesothelioma.