GPC3 expression in PSTT and other uterine and cervical lesions. A. H&E of PSTT showing large tumor cells mixed with smaller mononucleate tumor cells (20×). B. GPC3 immunostain of PSTT showing focal strong reactivity, particularly in large tumor cells, surrounded by smaller tumor cells with weak pale staining (20×). C. H&E depicting large pleomorphic tumor cells in PSTT, some of which are multinucleate (60×). D. GPC3 immunostain of PSTT with variable reactivity, ranging from intense to very weak. Larger cells appear to have the strongest reactivity (60×). E. H&E of PSN showing degenerated intermediate trophoblasts in a hyalinized background (20×). F. GPC3 immunostain of PSN depicting weak cytoplasmic reactivity (20×). G. H&E of endometrial adenocarcinoma (40×). H. GPC3 immunostain of endometrial adenocarcinoma showing no reactivity (40×) I. H&E of uninvolved, nonneoplastic endometrium (20×). J. GPC3 immunostain showing no reactivity in nonneoplastic endometrium (20×).