Fig. 9: Optimization of p57 immunostaining for diagnosis of complete hydatidiform moles.

a Complete hydatidiform mole with features of the early form, including variably bulbous villous shapes, trophoblastic hyperplasia, and myxoid slightly cellular villous stroma. b Villous stromal cells and some cytotrophoblastic cells demonstrate p57 expression on a preparation from an outside laboratory, raising doubt about the morphologic impression, but there is an inappropriate level of nonspecific cytoplasmic staining. c, d Preparations performed in our laboratory show the typical morphologic features of an early complete hydatidiform mole (c), with lack of p57 expression in villous cytotrophoblast and stromal cells (d), without any nonspecific cytoplasmic staining yet robust internal positive control in intermediate trophoblastic cells to assure an adequate reaction. Genotyping confirmed this as an androgenetic conception.