Correlation of p53 expression with morphological features in complete and partial hydatidiform moles

Hydatidiform mole, the most common form of gestational trophoblastic disease, presents as complete or partial form. Complete hydatidiform mole (CHM) usually presents with prominent histological criteria, whereas partial hydatidiform mole (PHM) shows a wide spectrum of presentations depending on gestational age. Molecular markers enhance the understanding of the variation and heterogeneous presentation of molar pregnancies, as well as their biological potential and behavior. This retrospective study included 50 CHM and 50 PHM specimens, terminated in first trimester via suction curettage. A second histopathological review of slides stained with hematoxylin and eosin was conducted, as well as a selection of representative tissue slides for p53 immunostaining. This study aimed to determine the precise correlation between specific morphological criteria and the patterns of p53 immunoexpression. Semi-quantitative analysis of samples for both pathological criteria and p53 immunostaining was performed. p53 positivity was defined as follow: the percentage of positive cells/nuclei: + (10-40%); ++ (40-70%); +++ (>70%); and staining intensity was scored as: 1 – weak, 2 – moderate, and 3 – strong intensity. P53 expression was estimated on at least 200 nuclei of cytotrophoblasts per slide. Significant difference in p53 expression exist between CHM and PHM in staining intensity. CHM shows significant correlation of p53 positivity with hydrops, central cisterns and atypia. In PHM trophoblast pseudoinclusions demonstrate strong significant correlation with p53 positivity. The irregular pseudoinclusions demonstrate lower expression compared with round or oval, being consistent with benign behavior of PHM. Prominent morphological criteria strongly correlate with p53 immunoexpression for both CHM and PHM.