ABSTRACT
Background and objective: The distinction of hydatidiform mole from hydropic abortion remains a problem because of interobserver and intraobserver variability. This study aimed to determine the utility of P57[Kip2] as a diagnostic marker in differentiating complete hydatidiform mole from its mimics
Methods: A total of 97 formalin fixed paraffin embedded material including forty cases of complete hydatidiform mole, 36 cases of partial hydatidiform mole and 21 cases of hydropic abortion were selected randomly from the files of histopathology laboratory of Maternity Teaching Hospital in Erbil. The samples were reviewed by two pathologists, afterward; immunohistochemical staining was performed by using a P57[Kip2] marker. We considered P57[Kip2] positive only if nuclear P57[Kip2] staining was identified in at least 10% or more of all in a tissue section
Results: Negative immunostaining was seen in 77.5% of the complete hydatidiform mole in both villous cytotrophoblast and stromal cells. In contrast, 86.1% of partial hydatidiform mole showed positive immunostaining for P57[Kip2]. All cases of hydropic abortion 100% were positive for P57[Kip2] immunostaining. In all gestations, P57[Kip2] was strongly expressed in decidua which served as internal positive control. The concordance between the initial histological diagnosis and P57[Kip2] immunostaining was statistically significant [P <0.001]
Conclusions: P57[Kip2] immunostaining is a highly sensitive and specific marker for diagnosis and classification of hydatidiform mole. P57[Kip2] staining has the advantage of differentiating hydropic abortuses from the complete hydatidiform mole