Expression of p57 immunomarker in the classification and differential diagnosis of partial and complete hydatidiform moles

BACKGROUND: Hydatidiform mole (HM) is characterized histologically by cystic swelling of the chorionic villi, accompanied by variable trophoblastic proliferation. The most important reason for the correct recognition of moles is that they are associated with an increased risk of persistent trophoblastic disease (invasive mole) or choriocarcinoma. AIMS AND OBJECTIVES: The aim of the study was to determine whether there is any role of p57 in differentiating partial and complete moles by immunohistochemical staining. MATERIALS AND METHODS: A prospective observational study was undertaken in which 40 cases of molar pregnancy included over a period of 2 years. Detailed clinical and family histories were obtained from each patient. Histopathological examination followed by immunohistochemical study with p57 done in each case. Ultrasonography findings and serial titers of serum beta-human chorionic gonadotropin were noted whenever necessary. RESULTS: Among the forty cases included, 25 (62%) had complete molar (CM) pregnancy, whereas the rest 15 (38%) had partial mole (PM). Both CM and PM were more pronounced in the age group of 20–25 years (44% and 60%, respectively), and among nulliparous women (68% and 70% respectively), 17 (42.5%) mothers had a prior history of abortion. In the histologically unequivocal cases of complete mole, 96% (24 of 25) did not express p57 and a single case was focal positive. In contrast, it was strongly and continuously expressed in both villous cytotrophoblast and stromal cells in all cases of PM (15 of 15). CONCLUSION: p57 immunomarker is very helpful to diagnose and differentiate complete and partial HM.