Figure 3
Case 5: (a) Diffuse proliferation of large epithelioid cells with abundant dense eosinophilic cytoplasm and deciduoid features. Many of the cells are multinucleated. An atypical mitosis can be seen near the center of the figure. (b) Higher magnification showing a detail of the morphology of the cells. An atypical mitosis is present in the center of the figure. (c) Area of the same tumor in which the cells appear more pleomorphic and some of them are elongated. Two mitotic figures are present toward the right upper corner. (d) The nuclei of the neoplastic cells are markedly pleomorphic and strongly positive for WT1. (e) Tumor cells strongly reacting for mesothelin along the cell membrane. Case 10: (f) Pleomorphic epithelioid cells diffusely infiltrating the skeletal muscle of the chest wall. (g) Higher magnification showing, in more detail, the morphologic features of the neoplastic cells which exhibit single or multiple nuclei and often contain a large nucleolus. Note that the cell cytoplasm is less abundant than that seen in case 5. A tripolar mitosis is seen in the lower left corner of the figure. (h) An area of the same tumor in which the neoplastic cells appear to be discohesive and are sometimes arranged in a poorly formed tubular array.
