P57 < Sup > K1p2 < / Sup > And Phlda2 Protein Expression In The Diagnosis Of Hydatidiform Mole

BackgroundHydatidiform mole(HM), the most common gestational trophoblastic disease, can be classified as complete(CHM)or partial(PHM)on the basis of both pathology and genetic origin. Histologic examination Histologic diagnosis of hydatidiform mole is currently the main way. Accurate classification of a given case is clinically important since there are differene consequences for the prognosis and management of each condition. Traditionally, hsitologic description established that CHM exhibits uniwersal villous dedma, extensive cavitation, circumferential trophoblastic hyperplasia and lack of blood vessels.It become difficult to identified CHM and PHM correctly when classical features may not be fully developed. This has become more evident with routine use of through vaginal ultrasound examination and maternal chorionic gonadotropin monitoring in the management of pregnancy, which has resulted in most molar pregnancies being evacuated in the first trimester, before the development of theclassic histologic features. The analysis of nuclear DNA microsatellite polymorphisms is especially well suited for this purpose because it is capable of determining the number and parental origin of alleles in even small amounts of fixed tissue from paraffin blocks. However, such molecular diagnosis methods are technically difficult, relatively costly, and not universally available. Thus, a time-and cost-effective ancillary tool that is available in most laboratories would be helpful. The p57KIP2and PHLDA2(IPL/TSSC3)are paternally imprinted gene expressed only from the maternal allele. As expected, lack of its protein product has been demonstrated in immunohistochemistry(IHC)-based studies on CHM but not in those on non-CHM, suggesting that p57KIP2and PHLDA2(IPL/TSSC3)IHC can be helpful in distinguishing CHM.from its mimicsObjectivesTo investigate the value of combined use of paternally imprinted gene product p57K1P2and PHLDA2immunohistochemistry and flow eytometry in the difierential diagnosis of placental hydropic diseases.Material and MethodsSpecimens of29cases of mole pregancy,formerly diagnosed as complete hydatidiform moles(CHM, n=13), and partial hydatidiform moles(PHM, n=16) respectively, were reviewed by a senior pathologist. p57K1P2and PHLDA2immunohistochemical staining and flow cytometry DNA ploidy analysis were performed in all29cases.Results1. Flow cytometry in all29molar cases suggested that14cases were triploidy or tetraploid (means these cases are PHM) and15cases were diploidy (means these cases are CHM).2. All flow cytometrically confirmed partial moles were both p57K1P2and PHLDA2positive.There was strong PHLDA2staining of the cytoplasm in virtually all cells of the villous cytotrophoblast, while p57K1P2was localized to the nucleus in a subset of those cells.3. All flow cytometrically confirmed complete moles cases were both p57K1P2and PHLDA2negative.ConclusionImmunohistochemistry for p57K1P2and PHLDA2serves as a practical and reliable diagnostic marker for the diagnosis of complete mole from partial mole. Combined p57KIP2and PHLDA2immunohistochemistry could increase the level of confidence when making this prognosticcally importantdiatinction.