Patients with this disorder can have multiple/recurrent CHMs that are morphologically, immunophenotypically, and clinically similar to conventional CHMs; specifically, they are p57-negative and appear to show a similar risk of persistent gestational trophoblastic disease but are characterized by biparental diploidy rather than androgenetic diploidy [4]. This evidence concerns the gene CDKN1C and gestational trophoblastic neoplasm.