[Roles of p57KIP2 immunohistochemistry and flow cytometry in diagnosis of molar pregnancy].

OBJECTIVE

To study the value of combined use of paternally imprinted gene product p57(KIP2) immunohistochemistry and flow cytometry in the differential diagnosis of placental hydropic diseases.

METHODS

A total of 32 cases of hydropic placenta with DNA polymorphism information were collected, and the genetic results were used as basis for the diagnosis of complete hydatidiform moles (CHM), partial hydatidiform moles (PHM) or hydropic abortions. All cases were examined by histology, p57(KIP2) immunohistochemical staining (EnVision method) and flow cytometry DNA ploidy analysis. The p57(KIP2) immunohistochemical staining and DNA ploidy results were compared with the genetic results.

RESULTS

In CHM, p57(KIP2) negative rates were 95.2% (20/21), whereas all the 11 cases of non-CHM (7 cases PHM and 4 cases hydropic abortions) were positive (11/11). In 11 p57(KIP2) -positive cases, 7 cases with triploidy and 4 cases with diploidy by flow cytometry were proven to be PHM and hydropic abortions by genetic analysis, respectively. Overall, 96.9% (31/32) cases of hydropic placentas were correctly diagnosed by combined use of p57(KIP2) immunohistochemistry and flow cytometry.

CONCLUSIONS

p57(KIP2) immunohistochemical negativity is a reliable index for the diagnosis of CHM. Combined flow cytometry DNA ploidy and p57(KIP2) immunohistochemistry are useful in the pathological differentiation of CHM, PHM and hydropic abortions.