Figure 2
Case 4: (a) The tumor appears to be arranged in irregular solid nests of pleomorphic epithelioid cells. Some of the clusters exhibit prominent central necrosis. (b) Higher magnification of one of the nests showing that they are composed of neoplastic cells presenting a great variation in size in shape. (c) Two clusters of tumor cells, some of which have vacuolated cytoplasm most probably due to the presence of intracytoplasmic lumina. The surrounding stroma exhibits myxoid features. (d) Lymphatic vessel showing a lumen almost occluded by large pleomorphic tumor cells, some of which are multinucleated. (e) Immunostaining for podoplanin showing positivity along the lymphatic endothelium as well as in the cell membrane of the neoplastic cells. (f) Consecutive section showing nuclear and cytoplasmic positivity for calretinin. (g) Nuclear positivity for WT1 in some of the neoplastic cells. (h) Tumor cells exhibiting strong membranous reactivity for mesothelin.
