Immunohistochemical differentiation (p57) between complete mole, partial mole, and hydropic abortion

The histopathological distinction between complete hydatidiform mole (CHM), partial hydatidiform mole (PHM), and hydropic abortion (HA) represents a constant challenge in gynecological pathology practice, given the overlap of morphological features that can lead to diagnostic errors and inadequate therapeutic management. CHM, of androgenic origin, and PHM, resulting from dispermy, possess distinct potentials for malignant transformation, making accurate diagnosis fundamental for clinical monitoring and detection of gestational trophoblastic neoplasia. The use of p57KIP2 protein, a product of the CDKN1C gene located on chromosome 11p15.5, has become an indispensable immunohistochemical tool in this differentiation, as its expression is mediated by the maternal allele. This study aims to conduct a systematic literature review on the utility of p57 immunohistochemistry in the differential diagnosis of these gestational entities. The methodology was based on a bibliographic search in SciELO and LILACS databases, selecting studies published in the last decade that compared the expression pattern of p57 in CHM, PHM, and HA. The results show that the absence of p57 immunoexpression in CHM, in contrast to its positivity in PHM and HA, constitutes a highly sensitive and specific biomarker for the identification of CHM. It is concluded that the routine application of p57, combined with classical morphological criteria, is crucial to increase diagnostic accuracy and ensure appropriate clinical management, reducing diagnostic uncertainties in placental pathologies.(AU)