Expression of P57 Immunohistochemical Marker in Complete And Partial Hydatidiform Mole by Using Tissue Microarray Technique

Abstract

Back ground: Hydatidiform mole is an abnormal form of pregnancy divided in to two types; complete hydatidiform mole and partial hydatidiform mole. Detailed histopathologic examination remains to be the basis for the diagnosis of hydatidiform mole (HM). However, poor sampling, necrosis, and earlier uterine evacuation can lead to uncertainty in the diagnosis. Also, the criteria are subjective, resulting in considerable interobserver variability.The P57KIP2 gene is paternally imprinted and maternally expressed, and the presence of its protein product serves as an adjuvant marker for the nuclear maternal genome. Because a complete HM is the only type of conceptus lacking a maternal contribution, P57 KIP2 immunostaining is correspondingly absent, whereas it is present in partial HM and normal pregnancy. Aim of The Study: The purpose of this study is to evaluate the significance of the P57KIP2 immunohistochemical marker in the diagnosis of complete and partial hydatidiform mole , and to compare the P57KIP2 immunohistochemical marker results with that of ordinary Hematoxylin and Eosin slides histopathology results, in addition to evaluation of the Tissue Microarray Technique. Materials and Methods: Seventy cases of endometrial biopsies were obtained. Histologic evaluation of all cases was performed on routine sections stained with Hematoxylin and Eosin (H & E) and classified in complete and partial hydatidiform mole (30 each) and (10 cases) of normal product of pregnancy (abortion), and negative control slides were also used. These cases were collected during the period from December-2011 to Augest-2012. New technique is adopted in this research that is; Tissue microarray in which twelve small cores of representative tissue samples, each measure 3 mm in diameter sections from microarray block are cut using a microtome, mounted on a single microscope slide and then analyzed by staining with Hematoxylin and Eosin, then another section made for the immunohistochemical staining with P57 KIP2 antibody. Results: Regarding the expression of p57KIP2 IHC Marker in cases of PHM diagnosed previously by HE grade I, and they represented 13.3%. The correlation between the grades of the CHM and the results of the p57KIP2 IHC marker was statistically significant. Conclusion: P57KIP2 IHC marker is a useful adjunct, providing a definitive diagnosis of CHM. Errors in morphologic analysis resulted primarily in over diagnosis of PHM are more frequent than in CHM. There are significant differences in correct classification of hydatidiform mole between using P57KIP2 IHC marker and using H&E stain Cases in grade I of CHM were correlated significantly with the errors in morphological analysis resulted primarily in over diagnosis of CHM. Tissue Microarray is a relatively simple method can be used in pathology laboratories to decreased assay volume, time and cost.