Complete hydatidiform mole (CHM) is differentiated from partial hydatidiform mole (PHM) by all of the following EXCEPT:
- A CHM is typically diploid (46XX or 46XY) with entirely paternal genome; PHM is usually triploid (69XXY)
- B p57 immunostaining is positive in CHM and negative in PHM ✓
- C CHM carries a higher risk of progression to gestational trophoblastic neoplasia than PHM
- D Histologically, CHM shows diffuse trophoblastic hyperplasia; PHM shows focal hyperplasia
Correct answer: B. p57 immunostaining is positive in CHM and negative in PHM
Explanation
p57 (KIP2) is a paternally imprinted, maternally expressed gene. In complete hydatidiform mole, the genome is entirely paternal (androgenetic), so there is NO maternal gene expression and p57 staining is negative/absent in villous cytotrophoblast and stromal cells. In partial mole, which retains one maternal haploid set, p57 is positive. Thus option B is the false statement — it inverts the result.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.