Case 7. (a) An area in which the neoplastic cells with deciduoid features exhibits a marked loss of cellular cohesion. The nuclei of the cells in the left upper corner are more pleomorphic and hyperchromatic. (b) Adjacent area to that shown in the previous photomicrograph in which the cells appear more pleomorphic, while still retaining some deciduoid features. A mitotic figure can be seen both in the lower left and lower right corners. (c) In this area of the same case, the cells exhibit prominent rhabdoid features. Case 21. (d) Low magnification in which most of the neoplastic cells have intracytoplasmic lumina. (e) Higher magnification of an adjacent area to better demonstrates the deciduoid morphology of the neoplastic cells. The intracytoplasmic lumina appear empty. (f) Area of the tumor in which some of the intracytoplasmic lumina contain granular, bluish material that is most probably proteoglycans. Case 12. (g) Lower power magnification of a deciduoid mesothelioma with prominent myxoid stroma. (h) Higher magnification showing the deciduoid features of the tumor.