Fig. 12: Nonmolar conceptions.

a Nonmolar digynic triploid conception has some mild irregular villous shapes, with some syncytiotrophoblastic snouts and trophoblastic islands suggesting trophoblastic hyperplasia, but villi with polarized trophoblast are present (lower right). b–d Three examples of nonmolar biparental conceptions with some abnormal villous morphology demonstrate a spectrum of abnormal irregular villous structures with some variable hydropic change, scalloping, mild trophoblastic hyperplasia, and trophoblastic inclusions, suggesting partial hydatidiform moles (b, double trisomy 16 and 21; c, triple trisomy 7, 13, and 20, see Norris-Kirby et al. [59]; d, no trisomy identified per genotyping).