Morphological, immunohistochemical and chromosome in situ hybridization in the differential diagnosis of Hydatidiform Mole and Hydropic Abortion

ObjectiveTo explore the utility of histological, immunohistochemical and chromosome in situ hybridization (CISH) test in the differential diagnosis of Complete Hydatidiform Mole (CHM), Partial Hydatidiform Mole (PHM) and Hydropic Abortion (HA).Study designWe analyzed the histological characteristics, p57kip2 and Factor VIII expression and CISH test in 38 cases with some diagnostic concerns, comprising 13 CHM, 14 PHM and 11 HA.ResultsOur results indicate that p57kip2 expression and the ploidy assessed by CISH were essential for the reclassification of 2 cases, one from CHM to PHM and another from PHM to HA, as well as for confirming the previous diagnosis in cases where there were conflicting features. p57kip2 expression is diagnostic if no cells at all present it (CHM) or when there are over 10% of cells expressing it (PHM and HA).ConclusionsWe concluded that there is no single criterion for the distinction of CHM, PHM and HA. So p57kip2 expression and CISH test can be used in association with the histological findings for the differential diagnosis of the three conditions in cases presenting some concern for definitive diagnosis.