Validity of P57kip2 immunohistochemical marker in differential diagnosis of molar pregnancy

Objective: The differentiation of complete mole from partial mole and hydropic abortion is very important for patient management. The aim of this study was to determine the validity of p57kip2 in the diagnosis of hydatidiform moleMaterial and Method: Immunohistochemistry with the P57kip2 antibody was done in formalin-fixed paraffin-embedded samples of hydropic abortion (n=20), simple abortion (n=20), partial hydatidiform mole (n=20) and complete hydatidiform mole (n=20). Immunoreactivity was recorded separately in the different cellular components, such as villous cytotrophoblast, extravillous trophoblast, syncytiotrophoblast, stromal cells, and decidual cells. Then data were analyzed with suitable statistical test. Results: In partial hydatiform mole and also in simple and hydropic abortion, nuclear P57kip2 expression was observed at high frequency in cytotrophoblast, villous stromal cells and maternal decidua, but was absent in syncytiotrophoblast. Absent of nuclear immunoreactivity of cytotrophoblasts was detected in the majority (95%) of complete hydatiform mole. Significant difference was seen for P57kip2 expression in complete hydatiform mole in comparison with hydropic abortion (P=0.001) and partial hydatiform mole (P=0.001).Conclusions: This study confirms that P57kip2 immunohistochemistry can reliably identify most cases of complete hydatidiform mole and distinguishes it from hydropic abortions and partial hydatidiform mole.