Complementary role of p57kip2 immunostaining in diagnosing hydatidiform mole subtypes

Abstract

Objectives Gestational trophoblastic disease comprises of a spectrum of pregnancy-related tumours which includes complete (CHM) and partial hydatidiform moles (PHM). Accurate diagnosis and subclassification of HM subtypes are crucial as prognosis differs. Histopathological examination using haemotoxylin and eosin (H&E) staining remains the basis for diagnosing HM, with only 80% accuracy. p57kip2 is a cyclin-dependent kinase inhibitor (CDKI) protein and is strongly paternally imprinted, being expressed from maternal allele. Therefore, complete mole (CHM) with only paternal genome has nearly absent expression of p57kip2 compared to partial mole (PHM) having both paternal and maternal genomes. This study is aimed to determine usefulness of p57kip2 immunohistochemistry (IHC) analysis in the diagnosis of HM subtypes. Methods A total of 82 archived paraffin embedded HM tissues with subtypes classified based on H&E staining – 39 (47.5%) CHM, 41 (50.0%) PHM and two (2.43%) unclassified molar pregnancy were retrieved. All tissue samples were subjected for p57kip2 IHC analysis and HM subtypes were then reclassified. Results A total of 66 cases (80.5%) were re-classified as CHM, 14 cases (17.1%) as PHM and two cases (2.4%) were decidual and cystic tissues. Analysis using p57kip2 immunostaining showed a diagnostic discrepancy of 33.0% from routine H&E staining and helps to improve the characterisation of the HM subtypes specifically at early gestations which have less distinctive morphologies. Conclusions IHC using p57kip2 monoclonal antibody should be considered as a routine ancillary test to H&E in improving the diagnosis of HM subtypes particularly in developing countries with limited resources.

Diagnostic Utility of TSSC3 and RB1 Immunohistochemistry in Hydatidiform Mole

“…Interestingly, this observation is also in individuals with Asian heritage who live in Western countries [2]. The reported incidence of HMs was highest in the 2 of 14 South-East Asia countries, Indonesia, India and Turkey, with incidence ranging from 2 to 12 per 1000 live births [3]. The incidence of HMs in Malaysia was reported as 2.6 per 1000 live births [4].…”

“…There is a distinct geographical distribution of HMs. Estimates from studies across the world suggest the incidence of HMs is higher in Asian countries (0.81-4.4 per 1000 live births) compared to Western countries (0.66-1.21 per 1000 live births) [1][2][3][4]. Interestingly, this observation is also in individuals with Asian heritage who live in Western countries [2].…”