Pre‐operative classification of molar pregnancy: How good is ultrasound?

Abstract

Background: Histopathology is the reference standard for diagnosing hydatidiform molar pregnancy (HMP). Aim: To assess the performance of pre-operative transvaginal ultrasound (TVS) to predict HMP. Materials and Methods: A retrospective diagnostic accuracy study was performed on women who had both TVS and histopathological examination of uterine curettings between January 2011-February 2017. TVS diagnosis of partial MP (PMP) included assessment of fetal parts and/or empty gestational sac with small cystic spaces adjacent to gestational sac. TVS diagnosis of complete MP (CMP) included assessment of complex, echogenic intra-uterine mass(es) containing multiple small cystic areas. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive and negative likelihood ratios (PLR/NLR) for TVS were reported. Reference standard was histology. Results: There were 4917 consecutive women who underwent TVS; 1636 underwent surgical curettage for miscarriage. Forty out of 4917 (0.6%) had HMP histologically; 25/40 (62.5%) had suspected HMP and 15/40 (37.5%) did not; 24/40 (60.0%) had CMP of which 19/24 (79.1%) were suspected on TVS and 5/24 (20.8%

The diagnostic value and accuracy of ultrasound in diagnosing hydatidiform mole: A systematic review and meta-analysis of the literature

“…It is well documented the HM can present in similar ways or even mimic a miscarriage, 33 with the most common symptom being vaginal bleeding. 13 Stamatopoulos et al 26 suggests this being the reason practitioners misdiagnose HM for a miscarriage, alongside the lack of sonographic characteristics that suggest the disorder. Farquharson & Stephenson 34 illustrate how PM can be easily misdiagnosed for an empty sac, which can be explained by the enlarged placenta or cystic changes within the uterus that mimic a HM.…”

“…With warranting symptoms, there is a higher expectancy for abnormal US findings. 28 Stamatopoulos et al 26 study highlights that EPU have a higher detection rate for HM, and therefore it can be assumed that the misdiagnosis rate should be lower. Yet, this statement does not support the descriptive data, as there was no correlation between the studies performed at the EPU having a lower misdiagnosis rate compared to routine US screening.…”

“…Stamatopoulos et al 26 and Alushani et al 30 had methodologies that varied from the others as they investigated transvaginal US (TVU) only, reducing the available sample size. The descriptive data supports this as there were only 40 cases in Stamatopoulos study.…”

“…The descriptive data supports this as there were only 40 cases in Stamatopoulos study. 26 The other studies included both transabdominal and TVU scans, giving a better representative sample of US in the detection of HM.…”

“…Another limitation of the Ross et al 15 methodology was that there was a range of practitioners performing the scan, which could influence the false negative rate in such an operator dependent modality. 31 Kirk et al 25 and Stamatopoulos et al 26 had similar methods and declared that specialising Sonographers or Radiologists performed the reviews and or undertook the initial diagnosis, which could reduce the false negative rate. When considering false negative rates, Jaunxiaux et al 29 findings are limited as it was not declared who reviewed the images.…”