paternal mole

Synopsis

 69, XXX or 69, XXY
 one haploid set of maternal chromosome and two haploid sets of paternal chromosome

Mechanisms

 duplication of a spermatozoid genome after the fecondation (diandric homozygous form)
 fecondation of the ovocyte by two spermatozoids (dispermic heterozygous form)

Phenotype

 macerated fetus
 +/- hypotrophic fetus
 +/- IUGR (intra-uterine growth retardation)
 3-4 fingers syndactyly
 3-4 toes syndactyly
 facial dysmorphy
 voluminous placenta (placental hypertrophy)
 thick placenta
 huge placental vesicules
 pseudo-molar placenta or partial mole
 mixed appearance of normal placental villi and hydropic villi with irregular limits
 vascular slits with pycnotic erythroblasts
 placental villous edema
 placental villous cysts
 placental villous citernae
 focal and moderate trophoblastic hyperplasia (syncitiotrophoblast)
 echography: thick, multicystic placenta; big ovular cavity containing a fetus or an embryo (possible diagnosis at 1st trimester)