Single-cell reconstruction with spatial context of migrating neural crest cells and their microenvironments during vertebrate head and neck formation.

The dynamics of multipotent neural crest cell differentiation and invasion as cells travel throughout the vertebrate embryo remain unclear. Here, we preserve spatial information to derive the transcriptional states of migrating neural crest cells and the cellular landscape of the first four chick cranial to cardiac branchial arches (BA1-4) using label-free, unsorted single-cell RNA sequencing. The faithful capture of branchial arch-specific genes led to identification of novel markers of migrating neural crest cells and 266 invasion genes common to all BA1-4 streams. Perturbation analysis of a small subset of invasion genes and time-lapse imaging identified their functional role to regulate neural crest cell behaviors. Comparison of the neural crest invasion signature to other cell invasion phenomena revealed a shared set of 45 genes, a subset of which showed direct relevance to human neuroblastoma cell lines analyzed after exposure to the in vivo chick embryonic neural crest microenvironment. Our data define an important spatio-temporal reference resource to address patterning of the vertebrate head and neck, and previously unidentified cell invasion genes with the potential for broad impact.

Fetal giant right cervical cyst causing severe tracheal compression: A case report.

RATIONALE: Fetal giant cervical cyst (FGCC) is a rare congenital anomaly. Sometimes FGCC may extend into the mediastinum, and result in severe tracheal compression, which is a life-threatening event at birth. PATIENT CONCERNS: We present a rare case of FGCC, which extended from the right neck into the superior mediastinum, and resulted in severe tracheal compression. DIAGNOSES: An FGCC was observed by ultrasonography and magnetic resonance imaging (MRI) at 27+4 weeks' gestation (WG). Fetal MRI at 35+1 WG showed that the FGCC was 3.3 × 8.2 × 7.5 cm and extended from the right neck into the superior mediastinum. Severe tracheal compression was observed and the inside diameter of the narrowest section of tracheostenosis appeared thread-like and measured only 0.1 cm. INTERVENTIONS: Cervical cyst reduction was performed prenatally under ultrasound guidance to alleviate the tracheal compression and maximize the chance of fetal survival 2 days before birth. At 36+3 WG, cesarean section was performed, and a female neonate was immediately delivered and intubated (3.5-mm tube) by an experienced anesthesiologist. Neonatal intralesional sclerotherapy and cystic component aspiration as guided by digital subtraction angiography were performed under general anesthesia. Anesthesia was maintained only with sevoflurane 3% in 2 L/min oxygen. Extubation was performed soon after surgery. OUTCOME: The neonate recovered uneventfully and was discharged 2 days postoperatively. After 140 days of follow-up, the neonate had recovered completely. LESSONS: If an FGCC is suspected by abdominal ultrasound, a fetal MRI is recommended to assess the severity of tracheal compression before birth, if feasible. An anesthesiologist should assess the risk of intubation failure at birth according to those results. If fetal severe tracheal compression is detected and it may result in inability of intubation at birth, prenatal cervical cyst reduction under ultrasound guidance may be effective for alleviating tracheal compression at birth, if feasible. This could maximize the chance of fetal survival. Improvement of fetal short- and long-term outcomes is important.

Intubation Using C-MAC Video Laryngoscope During Ex Utero Intrapartum Treatment Featuring Upper Airway Neck Mass: A Case Report.

Ex utero intrapartum treatment procedures are mainly indicated to secure the airways of fetuses featuring a risk of obstruction at birth while ensuring uteroplacental circulation. This report documents a successful intubation case with a C-MAC video laryngoscope during an ex utero intrapartum treatment procedure in a newborn featuring an infiltrative neck mass. Despite technical challenges faced in this procedure, the C-MAC video laryngoscope allowed an optimal view of airway structures. This novel approach, where laryngoscopy relies on the usage of C-MAC to optimize intubation conditions, may lead to increased chances of success in this particular scenario.

What are the prevalence, characteristics and significance of fetal lateral neck cysts detected in an early anatomical scan?

PURPOSE: This study evaluated the association of fetal lateral neck cysts (FLNC) with adverse pregnancy outcomes, in relation to specific sonographic characteristics and co-existing findings. METHODS: Pregnancies in which FLNC were detected by a single examiner in early anatomical scans (14-16 weeks) were included. Data regarding the pregnancy and its outcome were retrieved from telephone-based questionnaires, patient charts and from the examiner's reports. RESULTS: 654 cases of FLNC were detected among 9446 early anatomical scans (6.9%). Complete data regarding 219 pregnancies were available. FLNC were significantly more prevalent in males (65.2%). The prevalence of heart malformations was 3.2% [all were non-isolated cases or with abnormal nuchal translucency (NT) and/or nuchal fold (NF)]. Amniocentesis performed in 165 pregnancies was abnormal in 1.2%. Among 206 children born from this cohort, adverse medical outcomes were reported in 5.3%. The likelihood of adverse pregnancy outcomes was significantly higher in non-isolated cases and in cases with abnormal NT or NF. Sonographic characteristics such as cyst size and bilateral findings were not linked to adverse pregnancy outcomes. CONCLUSION: Isolated FLNC are benign findings which do not require additional work up. FLNC with additional sonographic abnormalities are associated with a significantly increased risk for adverse pregnancy outcomes.

BPI-fold (BPIF) containing/plunc protein expression in human fetal major and minor salivary glands

Abstract The aim of this study was to determine expression, not previously described, of PLUNC (palate, lung, and nasal epithelium clone) (BPI-fold containing) proteins in major and minor salivary glands from very early fetal tissue to the end of the second trimester and thus gain further insight into the function of these proteins. Early fetal heads, and major and minor salivary glands were collected retrospectively and glands were classified according to morphodifferentiation stage. Expression of BPI-fold containing proteins was localized through immunohistochemistry. BPIFA2, the major BPI-fold containing protein in adult salivary glands, was detected only in the laryngeal pharynx; the lack of staining in salivary glands suggested salivary expression is either very late in development or is only in adult tissues. Early expression of BPIFA1 was seen in the trachea and nasal cavity with salivary gland expression only seen in late morphodifferentiation stages. BPIFB1 was seen in early neural tissue and at later stages in submandibular and sublingual glands. BPIFA1 is significantly expressed in early fetal oral tissue but BPIFB1 has extremely limited expression and the major salivary BPIF protein (BPIFA2) is not produced in fetal development. Further studies, with more sensitive techniques, will confirm the expression pattern and enable a better understanding of embryonic BPIF protein function.

Antenatal hemorrhage of a cervical lymphatic malformation presenting as a draining neck mass: An unusual presentation.

Lymphatic malformations in the neck can present as large fetal neck masses causing airway obstructions with potential perinatal demise and can pose a therapeutic challenge. We present a rare case of prenatally diagnosed large fetal neck mass with features of lymphatic malformation with intralesional hemorrhage of uncertain origin. Postnatal evaluation showed a complex cystic-solid lesion eroding through the skin with an open wound that made it clinically hard to differentiate from a teratoma. Given that malignancy could not be completely ruled out, surgery was favored. Final pathology showed a complex lymphatic malformation with intralesional hemorrhage, despite having no associated capillary, venous or arterial malformations.

Desarrollo de Cara y Cuello en Vertebrados / Face and Neck Development in Vertebrates

El desarrollo embrionario de las regiones facial, del cuello, cavidades nasales y oral en conjunto con las glándulas asociadas, involucra el crecimiento y fusión tridimensional de múltiples procesos. Existe participación de elementos derivados de las 3 capas embrionarias locales y adicionalmente de células derivas de la cresta neural, procedentes de los rombómeros vecinos. Estas últimas se ven involucradas en la formación del esqueleto local, entre otras estructuras. El estudio evolutivo desde los vertebrados sin mandíbula nos enseña como se expresan los genes Hox en las diferentes especies, y como esto determina la formación de diferentes estructuras. En la siguiente revisión contemplamos algunos aspectos morfológicos, moleculares y evolutivos básicos del desarrollo facial y cervical, con énfasis en mamíferos con un epílogo referente a las malformaciones de la región en humanos.

The embryonic development of the facial area, neck, nasal, oral and pharyngeal cavities with glands, involves growth and fusion of multi-dimensional processes. There is involvement of elements from the embryo-derived local 3 layers cells further neural crest derived cells from the neighbors rhombomeres. The neural crest cells are involved in the formation of local skeleton, among other structures. The study of evolution from jawless vertebrates shows us how Hox genes are expressed in different species, and how this determines the formation of different structures. The following review contemplate some morphological, molecular and evolutionary basis of facial and neck development, with emphasis on mammals with an epilogue concerning to the face and neck malformations in humans.

A hypothesis on the morphologic differences between Unna and Miescher nevi on the head and neck, based on embryologic bases.

Unna and Miescher nevi show very different morphologic features. The main difference is that melanocytes involve mainly the papillary dermis in Unna nevi, whereas they widely penetrate the reticular dermis in Miescher nevi. The reason for this behavior is not totally understood, but anatomical location might play a role, since because Unna nevi are mainly found on the trunk, whereas Miescher nevi are mainly found on the face. We decided to test this hypothesis in relative easy way: dermis from the frontal, temporal, maxillary, and mandibullary regions derives from the neural crest, whereas the dermis of the parietal/occipital regions originates from the paraxial mesoderm (somites and somitomeres). Therefore, we studied the morphology of 137 acquired melanocytic nevi from the head and neck and classified their locations in 7 areas: occipital, temporal, parietal, frontal, face, high neck, and low neck. From such areas, we distinguished 4 groups: area A (parietal + occipital + low neck); area B (face + temporal + frontal + high neck); area 1 (parietal and occipital); and area 2 (temporal and frontal). In region A, 97.30% of the nevi were of Unna type. In region B, 89.00% were of Miescher type. Region A had 76.60% of Unna type nevi, whereas region B had 98.89% of Miescher nevi. In area 1, 100% of the nevi were of Miescher type. In area 2, 86.67% of the nevi were of Unna type. Region 1 had 86.67% of the cranial Unna nevi, whereas region 2 had 100% of the cranial Miescher nevi. Moreover, 90.9% of the nevi from the low neck were of Unna type. In the high neck, 20% of nevi were of Unna type. Finally, 90.90% of Unna nevi were in the low neck, whereas 80% of Miescher nevi were in the high neck. We concluded that these findings supported the hypothesis that the embryologic differences of these areas of head and neck might play a role in the morphology of Unna and Miescher nevi.

The relationship between maternal body mass, smoking status and ethnicity and first trimester nuchal translucency thickness.

OBJECTIVE: To investigate the existence of a relationship between maternal body mass, maternal ethnicity and maternal smoking status and nuchal translucency (NT) in the first trimester of pregnancy. METHODS: NT measurements from 130 339 euploid, singleton pregnancies were converted to NT multiples of the median (MoM) and delta NT using expected medians determined using regression analysis. Relationships between maternal body mass index (BMI), maternal weight, maternal ethnicity and maternal smoking status and NT MoM and delta NT were examined. RESULTS: NT increased with gestational age. Uncorrected NT MoM and delta NT demonstrated small but significant positive relationships with either maternal BMI or maternal weight. Both NT MoM and delta NT were slightly, but significantly, increased in smokers compared to non-smokers and Afro-Caribbean compared to Caucasians, and slightly, but significantly, decreased in Asians compared to Caucasians. CONCLUSION: Although statistically significant, all the changes reported are likely to be too small to be relevant in terms of correcting in prenatal screening.

Maternal serum human placental growth hormone at 11 to 13 weeks in trisomy 21 and trisomy 18 pregnancies.

OBJECTIVE: To investigate the maternal serum concentration of human placental growth hormone (hPGH) in trisomy 21 and trisomy 18 pregnancies at 11 to 13 weeks of gestation and to examine the possible association between fetal nuchal translucency (NT) thickness and maternal serum free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A). METHODS: The maternal serum concentration of hPGH at 11 to 13 weeks was measured in a case-control study from 28 pregnancies with fetal trisomy 21, 28 with trisomy 18 and 112 pregnancies with euploid fetuses. The median hPGH multiple of the median (MoM) in trisomy 21 and trisomy 18 pregnancies were compared with euploid pregnancies. RESULTS: Serum hPGH was significantly lower in trisomy 21 (0.93 MoM) and trisomy 18 (0.62 MoM) compared to euploid pregnancies (1.02 MoM). There was a significant association between serum hPGH and PAPP-A in both the euploid (r = 0.258, p = 0.006) and trisomy 21 pregnancies (r = 0.410, p = 0.030) but not in trisomy 18 pregnancies (p = 0.445). CONCLUSION: In the first trimester, serum hPGH in trisomy 21 and trisomy 18 pregnancies is reduced. This is the opposite of findings in previous studies reporting that in the second trimester, trisomy 21 and 18 pregnancies have increased hPGH.

Abnormal Shh and FOXC2 expression correlates with aberrant lymphatic development in human fetuses with increased nuchal translucency.

OBJECTIVE: Previous research in fetuses with increased nuchal translucency (NT) showed abnormal lymphatic endothelial differentiation characteristics, including increased vascular endothelial growth factor (VEGF)-A expression, and aberrant smooth muscle cells (SMCs) surrounding enlarged jugular lymphatic sacs (JLS). We hypothesized that abnormal Sonic hedgehog (Shh) expression would result in altered VEGF-A signaling in the lymphatic endothelial cells of the JLS and that aberrant acquisition of SMCs could be caused by downregulation of forkhead transcription factor FOXC2 and upregulation of platelet-derived growth factor (PDGF)-B in the lymphatic endothelial cells of the JLS. METHODS: Five trisomy 21 fetuses and four controls were investigated using immunohistochemistry for Shh, VEGF-A, FOXC2 and PDGF-B expression in the lymphatic endothelial cells of the JLS. RESULTS: An increased Shh, VEGF-A and PDGF-B expression, and decreased FOXC2 expression were shown in the lymphatic endothelial cells of the JLS of the trisomic fetuses. CONCLUSIONS: Increased Shh and VEGF-A expression is correlated with an aberrant lymphatic endothelial differentiation in trisomy 21 fetuses. The SMCs surrounding the JLS can possibly be explained by an increase of PDGF-B-induced SMC recruitment and/or differentiation. This underscores earlier findings that indicate the loss of lymphatic identity in trisomy 21 fetuses and a shift towards a blood vessel wall phenotype.

Testing for 22q11 microdeletion in 146 fetuses with nuchal translucency above the 99th percentile and a normal karyotype.

The aim of this study was to examine the value of testing for a 22q11 microdeletion in fetuses with nuchal translucency (NT) above the 99th percentile (>3.5 mm). A 22q11 microdeletion results in the development of 22q11 deletion syndrome, a spectrum of disorders also known as DiGeorge/Velocardiofacial syndrome. A total of 146 pregnancies met the inclusion criteria of NT >3.5 mm between 11+2 and 13+6 weeks' gestation, no structural malformation and normal karyotype. Chorionic villi samples were tested with either multiplex ligation-dependent probe amplification (MLPA) or fluorescent in situ hybridization (FISH) analysis for 22q11 microdeletion. None were diagnosed with the microdeletion. The estimated prevalence of 22q11 microdeletion in these otherwise normal fetuses with increased NT is below 2.7%.

Frontomaxillary facial angle in screening for trisomy 21 at 11 + 0 to 13 + 6 weeks.

OBJECTIVE: Trisomy 21 is associated with a flat face, which can now be quantified by measurement of the frontomaxillary facial (FMF) angle. The aim of this study was to examine whether in trisomy 21 fetuses fetal nuchal translucency (NT) thickness and maternal serum free ss-human chorionic gonadotropin (ss-hCG) and pregnancy-associated plasma protein-A (PAPP-A) are independent of the FMF angle, and to estimate the performance of a first-trimester screening test for trisomy 21 that includes measurement of the FMF angle. METHODS: This was a prospective study in singleton pregnancies at 11 + 0 to 13 + 6 weeks of gestation in which three-dimensional volumes of the fetal head were obtained and measurement of the FMF angle performed immediately before fetal karyotyping by chorionic villus sampling (CVS). The women chose to have CVS after risk assessment by a combination of maternal age, fetal NT thickness and maternal serum free ss-hCG and PAPP-A. Regression analysis was used to examine the significance of the association within the euploid and within the trisomy 21 fetuses between the deviation from the normal median in FMF angle and the deviation in NT, free ss-hCG and PAPP-A. We estimated the detection rate (DR) and false positive rate (FPR) of first-trimester screening for trisomy 21 by measuring the FMF angle in all cases and of an alternative policy in which first-stage screening is by fetal NT and maternal serum biochemistry in all patients, followed by second-stage assessment of FMF angle only in those with an intermediate risk (1 in 51 to 1 in 1000) after the first stage. RESULTS: The FMF angle was measured in 782 euploid and 108 trisomy 21 fetuses. In the euploid fetuses the mean FMF angle decreased linearly with CRL from 83.5 degrees at a crown-rump length (CRL) of 45 mm to 76.4 degrees at a CRL of 84 mm. In the euploid fetuses the mean delta FMF angle was 0.0 (SD, 4.264) degrees and the respective values in the trisomy 21 fetuses were 7.172 (SD, 4.092) degrees . Incorporating the FMF angle in first-trimester combined screening increased the estimated DR from 90 to 94% at an FPR of 5% and from 85 to 92% at an FPR of 3%. In two-stage screening it would be necessary to measure the FMF angle in 12% of cases and the DRs would be 93 and 91% at FPRs of 5 and 3%, respectively. CONCLUSIONS: Measurement of the FMF angle improves the performance of first-trimester screening for trisomy 21.

Jugular lymphatic maldevelopment in Turner syndrome and trisomy 21: different anomalies leading to nuchal edema.

Increased nuchal translucency (NT), morphologically known as nuchal edema, is an ultrasound marker for aneuploidy. Turner syndrome presents with massive NT, called cystic hygroma. Conflicting data exist as to whether cystic hygroma and increased NT are different entities. Both are associated with jugular lymphatic distension. The authors investigated jugular lymphatics of trisomy 21, Turner syndrome, and normal karyotype fetuses. Fetuses were investigated using immunohistochemistry for blood vascular, lymphatic, and smooth muscle cell markers. Trisomy 21 fetuses showed nuchal cavities within the mesenchymal edema negative for endothelial markers. These were extremely large in Turner fetuses, showing similar characteristics. The skin showed numerous dilated lymphatics in the case of trisomy 21 and scanty small lymphatics in Turner fetuses. A jugular lymphatic sac was present in control and trisomy 21 fetuses and was enlarged in trisomy 21 cases. In Turner fetuses, no jugular lymphatic sac was observed. Nuchal edema in trisomy 21 and Turner syndrome appears to be a similar entity caused by different lymphatic abnormalities.

The use of nuchal translucency in contemporary obstetric practice.

Nuchal translucency sonography is the most powerful single prenatal marker for Down syndrome. Its detection rate is 75% at a 5% false-positive rate. The combination of nuchal translucency and maternal serum-free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A can identify 85% to 90% of fetuses with Down syndrome for a false-positive rate of 5%. This method can also identify more than 90% of fetuses with trisomies 18 and 13, Turner syndrome, and triploidy for a screen-positive rate of 1%.

Characteristics and outcome of fetal cystic hygroma diagnosed in the first trimester.

OBJECTIVE: The aim of this study was to determine the course of pregnancy and the neonatal outcome of fetuses with cystic hygroma diagnosed at 10-14 weeks' gestation. METHODS: Maternal and fetal data (nuchal translucency, karyotype, pregnancy outcome) in cases of fetal cystic hygroma, admitted or referred to our antenatal diagnostic centre, were prospectively entered into a computer database. Paediatric outcome was analysed when relevant. RESULTS: Some 72 fetuses had cystic hygroma. The mean size of the cystic hygroma was 7.9 mm. Chromosomal abnormalities were present in 52.7% of cases (38/72), including 14 cases (36.8%) of Down syndrome. A total of 34 chromosomally normal pregnancies gave rise to 18 live births (52.9%), with no visible serious structural abnormalities. The outcome of pregnancy was unfavourable (miscarriage, elective termination, serious structural abnormalities) in 77.7% of cases (56/72). The 18 live-born infants were followed up for 17-98 months. Sixteen infants developed normally, while 1 developed Noonan's syndrome and 1 had a urinary tract abnormality (pyelo-ureteral junction; PUJ). CONCLUSION: These data suggest that the prognosis of fetal cystic hygroma detected during the first trimester is poor, and show that sonographic evaluation of fetal nuchal translucency thickness in the first trimester is crucial.

Nuchal translucency measurement in first trimester Down syndrome screening.

(1) Approximately three in every four fetuses with Down syndrome have increased nuchal translucency (NT), which is a larger than normal build-up of fluid at the back of the neck. (2) The ultrasound measurement of NT between 11 and 14 weeks' gestation, in combination with the mother's age and the levels of placental biochemical markers in her blood, can be used to detect approximately 84% of fetuses with Down syndrome. (3) The accuracy of NT measurement is affected by fetal position, measurement technique, the type of risk-calculation software used, and the sonographer's experience and technical expertise. (4) A rigorous standardization and quality assurance system for NT measurement is needed before any test using NT ultrasound is offered universally. The cost of establishing such a program is unknown.

Nuchal translucency measurement and congenital heart defects: modest association in low-risk pregnancies.

OBJECTIVE: To assess the performance of nuchal translucency (NT) measurement in the first trimester of pregnancy as a marker for congenital heart defects (CHD) in the fetus in a low-risk obstetric population. METHODS: Nuchal translucency screening was offered over a 3-year period to consecutive pregnant women without known a priori risk factors and attending midwife practices in three different areas in the Netherlands. In chromosomally normal fetuses and infants from the study population the NT measurements were matched with CHD detected either prenatally or postnatally. RESULTS: NT screening was offered to 6132 women with an uptake of 83%. A total of 4876 NT measurements was performed. Pregnancy outcome data were available in 4181 cases (86%). Defects of the heart and great arteries (CHD) were diagnosed in 24 cases (prevalence 5.8/1000). Thirteen of these were classified as major (prevalence 3.1/1000). Two major CHD occurred in fetuses showing an increased NT at the first-trimester scan. The sensitivity of NT measurement > 95th and > 99th percentile for all CHD and for major CHD, was 8% and 15%, respectively. The positive likelihood ratios of NT > 95(th) and > 99th percentile for major CHD were 6, 5 and 33, respectively. CONCLUSION: In pregnancies without known risk factors also, an increased NT is associated with major cardiac defects in the fetus and therefore represents an indication for specialized fetal echocardiography. However, this association is too weak to envisage a role for NT measurement as single screening strategy for the prenatal detection of cardiac defects.