Imaging of the Fetal Face and Neck

Definition

• Cleft lip: failure of fusion of the left, right, or bilateral maxillary prominence with the medial nasal prominence. Concomitant cleft palate is present in 80% of cases. Least severe form involves the superficial vermilion border of the lip.

• Cleft palate: a result of incomplete fusion of the lateral palatal shelves, the nasal septum, and the primary palate. The cleft can be unilateral or bilateral. Least severe form is a bifid uvula.

• Clefts associated with hypo- or hypertelorism have an increased association with brain anomalies. ^,

• Hypotelorism and holoprosencephaly.

• Hypertelorism and dysgenesis of the corpus callosum and pituitary abnormalities.

• Clefts can be isolated defects or appear as part of a syndrome. Various genetic and environmental factors contribute to developmental risk. ^{, ,}

• Can be divided into the following types

  • Unilateral cleft lip (CL) with cleft palate (CP) (most common)

  • Unilateral CL without CP

  • Bilateral CL and CP

  • Midline CL and CP

  • Isolated CP

Incidence and Pathogenesis

• Incidence of CL with CP is approximately 1:700 live births and varies by geographic, racial, and ethnic groups; socioeconomic status; and environmental exposure.

  • Asian and Native American populations: 1:500

  • African populations: 1:2500

  • Non-Hispanic White and Hispanic populations: 1:1000

• Variation between sex and laterality ^{, ,}

  • CL±CP 2:1 male-to-female ratio

  • CP 2:1 female-to-male ratio

  • Cleft location 2:1 left-to-right ratio

• Genetics and associated anomalies

  • CL±CP is associated with a genetic syndrome in 30% of cases.

  • Isolated CP is associated with a genetic syndrome in 50% of cases.

  • Additional anomaly present in 30% of CL±CP.

• Embryology ^,

  • Upper lip and primary palate normally fuse by week 7.

  • Secondary palate forms by fusion of palatal shelf by week 12.

• CL or CP occurs if the frontonasal process of the face does not join the lateral maxillary prominences at about week 7. ^{, , ,}

• Normally developing fetal brain induces frontonasal development. Abnormality in the underlying brain can be associated with a midline facial cleft by week 4. ^{, ,}

• Environmental risk factors ^,

  • Smoking, alcohol, organic solvents, agricultural chemicals, folate and zinc deficiencies, retinoids, and anticonvulsant drugs.

Key Diagnostic Features

• Ultrasound can visualize beginning at 13–14 weeks of gestation but is less sensitive in detecting CL±CP prior to 18–20 weeks. ^, The presence of additional anomalies increases detection rates.

• Lips are best seen in coronal view; palate is best visualized from axial view. Three-dimensional ultrasound can help. ^{, ,}

• Unilateral CL±CP

  • Left-sided more common.

  • Obliquely aligned gap in the lip extends to the nose.

  • Profile view may demonstrate a hooked nose.

  • A gap between the maxilla and palate may be present.

• Bilateral CL±CP

  • Central mass protrudes below the nose.

  • Profile view may show an infranasal, premaxillary mass.

  • Standard view of the lips may be difficult to obtain.

  • If anterior palate is involved, a gap in the alveolar ridge of the maxilla may be visualized.

• Midline CL and CP

  • Absent central maxilla and upper lip.

  • Deformed nose, possibly even absent and replaced by a proboscis. The nose may be small or have a single nostril.

• Three-dimensional ultrasound may demonstrate the interior of the mouth better, enabling better visualization of the fetal palate; alveolar ridge disruption or premaxillary protrusion suggests presence of bilateral CL and CP. Better assessment of the posterior palate is also possible. ^{, ,}

• The amniotic fluid and placenta are usually unaffected. However, if swallowing is affected by CL or CP, polyhydramnios may result.

• When CL±CP is isolated, fetal growth is typically unaffected.

Differential Diagnosis

• Amniotic band syndrome (especially when the clefting does not follow embryonic developmental pathways)

• Facial mass

  • Nasal/oral teratoma (epignathus)

  • Anterior meningocele

  • Frontal encephalocele

  • Hemangioma/lymphangioma

  • Lymphangioma

  • Proboscis

  • Rhabdomyosarcoma

  • Macroglossia

• Frontonasal dysplasia

• Premaxillary agenesis, associated with holoprosencephaly

• Normal variant with delayed maxillary fusion

• More than 500 syndromes are associated with facial clefting, ^{, ,} including trisomy 13 and 18, Treacher Collins, Pierre Robin, Goldenhar, DiGeorge, Crouzon, Van der Woude, and Waardenburg. ^{, ,}

Associated Anomalies

• Lumbar and cervical spine (33%)

• Cardiac (24%)

• Chromosomal (10%), especially trisomy 13 ^7,8

• Polyhydramnios if defective swallowing

• Central CL or CP is typically associated with other facial findings, such as hypotelorism or cyclops. In this setting, there is increased incidence of holoprosencephaly and trisomy 13.

• Other associated syndromes include frontonasal dysplasia and premaxillary agenesis, which typically is associated with alobar holoprosencephaly.

Imaging

Management

Definition of the Lesion

• Congenital thin-walled cyst that contains lymphatic fluid.

• Septated or nonseptated.

• Can be located throughout the upper body:

  • Soft tissue at the posterior neck region (most common)

  • May extend cephalad to engulf the fetal head

  • May extend caudad to cover the dorsum of the fetus

  • Can be found in the mediastinum and axilla

• Alternative or historical names for cystic hygroma include cystic lymphangioma, lymphatic hamartoma, jugular lymphatic obstructive sequence, and hygroma cysticum.

Incidence and Pathogenesis

• Occurs in 1:100 pregnancies in first trimester. The subclassification of septated cystic hygroma occurs in 1:285 pregnancies.

• Arises from failure of primitive lymphatic tree to connect to the venous system. Blind lymphatic pouch results in dilation of the lymphatic sac.

Key Diagnostic Features

• Anechoic fluid-filled cavities that are encircled by soft tissue, usually located in the posterior neck.

• May be multiloculated with septations or simple in appearance.

• May involve the fetal head, back, axilla, or mediastinum.

• A thick midline band may be present posteriorly, formed by the nuchal ligament separating the bilateral jugular lymphatic sacs.

Differential Diagnosis

• Thickened nuchal translucency

• Neural tube defects (posterior encephalocele, cervical meningocele)

• Cystic teratoma

• Hemangioma

• Thyroglossal duct cysts

• Branchial cleft cysts

• Laryngocele

• Twin-twin transfusion syndrome in monochorionic-diamniotic twin gestations

• Fetal hydrops

Associated Anomalies

• Associated structural anomalies are seen in 33.8% of first-trimester cystic hygromas.

• Aneuploidy (50%)

  • Turner syndrome (28.3%)

  • Trisomy 18 (19.4%)

  • Trisomy 13 (9.0%)

  • Triploidy (4.5%)

  • Mosaic deletion of chromosomes have also been reported

  • When detected while crown-rump length is below 45 mm, lower rates of chromosomal abnormalities and higher proportion of normal birth shiftenteroutcomes

• Cardiac anomalies

  • Cardiac abnormalities account for 72.7% of the associated structural abnormalities.

  • Reported cardiac anomalies associated with cystic hygroma include hypoplastic left or right heart syndrome, tetralogy of Fallot, ventricular septal defect, and other complex cardiac anomalies.

  • In euploid fetuses, the incidence of major congenital heart disease was 4.3%.

• Syndromes reported in fetuses with cystic hygroma include Roberts syndrome, Cornelia de Lange syndrome, multiple pterygium syndrome, Noonan syndrome, and fetal akinesia sequence.

• Skeletal abnormality.

• Fetal hydrops.

• Intrauterine fetal demise.

Imaging

Management