Molecular and immunohistochemical characteristics of complete hydatidiform moles

Abstract

Molar pregnancy is a gestational trophoblastic disease that belongs to the category of precancerous lesions. On the other end of the spectrum are gestational trophoblastic neoplasms such as invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor, which are considered malignant tumors. Based on defined histopathological criteria, molar pregnancy is divided into partial and complete hydatidiform mole. Especially in the case of early complete mole, the diagnosis can be quite challenging and often necessitates additional molecular or immunohistochemical methods. The aim of this study was to assess the importance of additional molecular and immunohistochemical methods to accurately diagnose complete hydatidiform mole and to stress the importance of correct diagnosis and close follow-up of these patients. A total of 367 consecutive cases of spontaneous abortion were analyzed in a 3-year period. Eight cases with histopathological diagnosis of complete molar pregnancy were selected for further analysis. Apart from standard microscopic analysis, additional molecular and immunohistochemical analyses were performed in all eight cases. Most of the histopathological characteristics of complete molar pregnancy were present in all cases, together with complete absence of positivity for the p57 immunohistochemical marker in the cytotrophoblasts and villous stromal cells. The molecular analysis revealed androgenetic diploidy in seven cases and biparental diploidy in one case with more than three consecutive complete molar pregnancies. Additional immunohistochemical and molecular methods can considerably aid in the correct diagnosis of molar pregnancy.

Ectopic Hydatidiform Mole a Case Report

“…The pathologic criteria must be strict in the diagnosis of ectopic molars, as some studies have found that there may be an overdiagnosis of ectopic molar pregnancy [1,13]. However, diagnosis can be a challenge to the pathologist since the differences in hydropic abortions and molar pregnancy can be minimal, especially in early miscarriages [14], add to this, evaluation of the specimen depends on the experience of the examiner and might be highly subjective [15]. On the other hand immunohistochemical analysis using antibodies like p57 can distinguish between hydatidiform mole with its different types and hydropic miscarriage [14].…”

“…However, diagnosis can be a challenge to the pathologist since the differences in hydropic abortions and molar pregnancy can be minimal, especially in early miscarriages [14], add to this, evaluation of the specimen depends on the experience of the examiner and might be highly subjective [15]. On the other hand immunohistochemical analysis using antibodies like p57 can distinguish between hydatidiform mole with its different types and hydropic miscarriage [14]. When available, DNA flow cytometric analysis to determine ploidy helps to differentiate between complete mole and partial mole [2].…”