Isolated choroid plexus cyst or echogenic cardiac focus on prenatal ultrasound: is genetic amniocentesis indicated?

Role of Sonographic Second Trimester Soft Markers in the Era of Cell-Free DNA Screening Options: A Review

Soft markers are sonographic structural, nonspecific signs with little pathological significance, often transient, usually considered as normal variants. However, they may also be associated with chromosomal abnormalities. The most widely examined soft markers include absent or hypoplastic nasal bone (NB), intracardiac echogenic focus (IEF), ventriculomegaly (VM), thickened nuchal fold (NF), choroid plexus cyst (CPC), echogenic bowel, short long bones, and urinary tract dilation (UTD). Although the use of noninvasive prenatal testing (NIPT) has been spreading quickly in maternal–fetal medicine, it is not a diagnostic test and it still remains unavailable or cost-prohibitive for most of the population in many countries. After normal screening test results in the first trimester, there is no uniform consensus regarding the clinical significance of isolated soft markers for aneuploidy. Nowadays, the search for soft markers in an ultrasound is still part of clinical evaluation, and the interpretation of these findings is often a matter of debate. In the present review, we summarize the recent literature about the role of soft markers in the era of NIPT and propose an overview of the different clinical guidelines.

Society for Maternal-Fetal Medicine Consult Series #57: Evaluation and management of isolated soft ultrasound markers for aneuploidy in the second trimester: (Replaces Consults #10, Single umbilical artery, October 2010; #16, Isolated echogenic bowel diagnosed on second-trimester ultrasound, August 2011; #17, Evaluation and management of isolated renal pelviectasis on second-trimester ultrasound, December 2011; #25, Isolated fetal choroid plexus cysts, April 2013; #27, Isolated echogenic intracardiac focus, August 2013)

Soft markers were originally introduced to prenatal ultrasonography to improve the detection of trisomy 21 over that achievable with age-based and serum screening strategies. As prenatal genetic screening strategies have greatly evolved in the last 2 decades, the relative importance of soft markers has shifted. The purpose of this document is to discuss the recommended evaluation and management of isolated soft markers in the context of current maternal serum screening and cell-free DNA screening options. In this document, "isolated" is used to describe a soft marker that has been identified in the absence of any fetal structural anomaly, growth restriction, or additional soft marker following a detailed obstetrical ultrasound examination. In this document, "serum screening methods" refers to all maternal screening strategies, including first-trimester screen, integrated screen, sequential screen, contingent screen, or quad screen. The Society for Maternal-Fetal Medicine recommends the following approach to the evaluation and management of isolated soft markers: (1) we do not recommend diagnostic testing for aneuploidy solely for the evaluation of an isolated soft marker following a negative serum or cell-free DNA screening result (GRADE 1B); (2) for pregnant people with no previous aneuploidy screening and isolated echogenic intracardiac focus, echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1B); (3) for pregnant people with no previous aneuploidy screening and isolated thickened nuchal fold or isolated absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening through cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (4) for pregnant people with no previous aneuploidy screening and isolated choroid plexus cysts, we recommend counseling to estimate the probability of trisomy 18 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1C); (5) for pregnant people with negative serum or cell-free DNA screening results and an isolated echogenic intracardiac focus, we recommend no further evaluation as this finding is a normal variant of no clinical importance with no indication for fetal echocardiography, follow-up ultrasound imaging, or postnatal evaluation (GRADE 1B); (6) for pregnant people with negative serum or cell-free DNA screening results and isolated fetal echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend no further aneuploidy evaluation (GRADE 1B); (7) for pregnant people with negative serum screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and discussion of options for no further aneuploidy evaluation, noninvasive aneuploidy screening through cell-free DNA, or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (8) for pregnant people with negative cell-free DNA screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend no further aneuploidy evaluation (GRADE 1B); (9) for pregnant people with negative serum or cell-free DNA screening results and isolated choroid plexus cysts, we recommend no further aneuploidy evaluation, as this finding is a normal variant of no clinical importance with no indication for follow-up ultrasound imaging or postnatal evaluation (GRADE 1C); (10) for fetuses with isolated echogenic bowel, we recommend an evaluation for cystic fibrosis and fetal cytomegalovirus infection and a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C); (11) for fetuses with an isolated single umbilical artery, we recommend no additional evaluation for aneuploidy, regardless of whether results of previous aneuploidy screening were low risk or testing was declined. We recommend a third-trimester ultrasound examination to evaluate growth and consideration of weekly antenatal fetal surveillance beginning at 36 0/7 weeks of gestation (GRADE 1C); (12) for fetuses with isolated urinary tract dilation A1, we recommend an ultrasound examination at ≥32 weeks of gestation to determine if postnatal pediatric urology or nephrology follow-up is needed. For fetuses with urinary tract dilation A2-3, we recommend an individualized follow-up ultrasound assessment with planned postnatal follow-up (GRADE 1C); (13) for fetuses with isolated shortened humerus, femur, or both, we recommend a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C).

Choroid Plexus Cyst of the Fourth Ventricle Associated with Intermittent Obstructive Hydrocephalus

BACKGROUND

Choroid plexus cysts (CPCs) are a type of neuroepithelial cysts, benign lesions located more frequently in the supratentorial compartment. Symptomatic CPCs in the posterior fossa are extremely rare and can be associated with obstructive hydrocephalus.

CASE DESCRIPTION

A previously healthy elderly woman suffered intermittent attacks of headache and vomiting associated with gait instability. Magnetic resonance imaging documented a large cystic lesion occupying all the fourth ventricle. An endoscope-assisted fenestration of the lesion through a telovelar approach determined only temporary improvement, hence a second surgery with gross total resection of the cyst was performed, with successful long-term clinical and radiologic resolution. Histology revealed CPC.

CONCLUSIONS

Fourth ventricle symptomatic CPCs are extremely rare lesions, especially in the elderly. Their presence must be carefully evaluated as a possible rare cause of intermittent obstructive hydrocephalus. Even though cyst fenestration with restoration of the cerebrospinal fluid pathway represents the best treatment in the majority of cases, a more aggressive resection is sometimes necessary.

Comparison of single versus multiple echogenic foci in the fetal heart regarding risk of aneuploidy

OBJECTIVE

The purpose of this study was to investigate whether multiple echogenic cardiac foci (ECF) are associated with an increased risk of fetal trisomy 21 in our patient population.

METHODS

During a span of 38 months, all women found to have an ECF on obstetric sonography were identified as study patients and grouped into single- and multiple-ECF groups. Age- and race-matched patients were identified as a control group. Fetal anatomic sonographic examinations were assessed for other markers of aneuploidy and major abnormalities. The baseline risk for trisomy 21 was assessed by maternal serum screening or age alone if no serum screening had been performed. Trisomy 21 was assessed by amniocentesis or clinically at birth. Both univariate and multivariate analyses were used to assess for associations with trisomy 21.

RESULTS

Six of 71 patients (8.5%) with multiple ECF and 1 of 171 patients (0.6%) with a single ECF had trisomy 21. One of 242 control patients (0.4%) had trisomy 21. Logistic regression found multiple ECF (P < .008), the presence of a major finding or multiple minor findings (P = .0012), and a baseline risk for trisomy 21 of greater than 1 in 100 (P = .003) as independent associations with trisomy 21.

CONCLUSIONS

Our results suggest that finding multiple ECF is a stronger predictor of trisomy 21 than what is described for a single ECF.