Foetal imaging and anomaly detection is advancing at a rapid rate. As a result, detection of foetal craniofacial abnormalities is increasing. Ultrasound and magnetic resonance imaging are currently the imaging modalities most commonly used. The authors describe the detection of a nasal glioma at 20 weeks’ gestation, subsequent prenatal monitoring and postnatal management with surgical excision at 2 months of age. The world literature regarding prenatal diagnosis and management of craniofacial malformations is discussed.
The maxillofacial surgeon is encountering the foetus as a patient with increased frequency . With advances in foetal imaging, malformations and disease not previously appreciated are being diagnosed earlier . These advances allow for better planning at the time of delivery and allow for preparation and counselling of the parents. The maxillofacial surgeon is placed in a pivotal role in a multidisciplinary team involved in the management of the foetus, providing differential diagnosis and discussing treatment options and their timing.
Nasal gliomas are rare benign congenital lesion occurring in 1:20,000–40,000 live births, their diagnosis is rarely described prenatally . The authors report a case of nasal glioma that was recently presented to their maxillofacial department. They review the world literature on the rapidly advancing world of prenatal diagnosis and management of craniofacial abnormalities.
A 27-year-old (Gravia: 3 Para: 1) underwent routine obstetric ultrasonography at 20 weeks’ gestation that revealed a cranio-facial malformation (CFM). Pre-pregnancy, the mother had a BMI of 33.9. She was otherwise fit and well, with no known underlying medical conditions. The father was a healthy 33-year-old.
Ultrasound was repeated at 23 weeks at which time the foetal growth and amniotic fluid were normal. A soft tissue mass above and to the left of the nasal bones measuring 10 mm × 10 mm × 9 mm was noted. The mass appeared to have a single vessel supplying the area and the origin could not be determined but there was a suggestion that it was connected to the foetal brain. The orbits, palate, lips and nasal bones appeared normal with no obvious markers of chromosomal abnormality.
Magnetic resonance imaging (MRI) and repeat ultrasound were undertaken at 24 weeks’ gestation and were unable to determine whether extension into the right orbital cavity was present. A small defect in the floor of the anterior cranial fossa close to the mass was noted. The brain appeared normal and separate from the lesion. Ultrasound demonstrated that the mass had grown from 10 mm × 10 mm × 9 mm to 13 mm × 11 mm × 12 mm and was avascular. The foetus appeared otherwise normal.
At 28 weeks, MRI and ultrasound demonstrated continued growth of the lesion which measured 16 mm × 12 mm, there was no evidence of post septal extension into the orbital cavity. The underlying bone and brain appeared normal.
Ultrasound scanning was repeated every 2 weeks and the mass remained stable until 36 weeks’ gestation when it increased in size. MRI was performed and did not demonstrate any bony erosion or deep extension ( Fig. 1 ).
At 38 weeks + 4, the baby was delivered by spontaneous vaginal delivery without complication. He was clinically well, apart from requiring 3 days of phototherapy for mild jaundice. He appeared to have no neurological deficit. He had a 20 mm × 15 mm soft, light purple, non-tender, fluctuant, cystic mass on the left glabellar region that did not appear to obstruct his eyesight. The clinical appearance appeared to be that of a haemangioma. Blood for chromosomal analysis revealed mosaicism for the loss of the Y chromosome in approximately 50% of cells. No other abnormality was detected. A post natal MRI scan was performed which ruled out bony involvement ( Fig. 2 ).
At 2 months, the lesion had grown to 30 mm × 40 mm. There was concern that the baby’s binocular vision would eventually be affected by the mass, particularly the right temporal field ( Fig. 3 ). Surgical excision with primary closure was undertaken. Histology reported the lesion to be a glioma. At subsequent follow-up appointments, the area was found to have healed without complication.
Prenatal care is a complex process designed to ensure the health of both the mother and foetus. Typically this care involves, at a minimum, an ultrasound scan to detect common foetal anomalies. As in the above case, ultrasound was repeated every 2 weeks. The size of the lesion was measured and any changes in the size prompted further MRI investigation.
Generally ultrasound is used to confirm and document gestational age, foetal number, foetal well being and to detect any obvious anomalies . Currently it is possible to detect craniofacial malformations on ultrasound as early as the week 11 of gestation . If an anomaly is detected or an elevated risk of an anomaly being present is thought to occur, more detailed investigations can be undertaken.
Ultrasound was first used in the obstetric field in the 1950s and has become a standard investigation in most of the developed world due to its noninvasive nature. A number of advances have allowed ultrasound to maintain a prominent role in antenatal care. In the 1970s greyscale imaging and real-time sonography became available allowing capturing of the moving foetus. In the 1980s, colour and Doppler imaging were introduced. More recently three dimensional real-time imaging has emerged .
Once an anomaly has been noted on ultrasound the majority of authors would recommend MRI . When first used in the 1980s for foetal surveys it was a lengthy procedure and required foetal sedation. The use of single shot fast spin-echo T2-weighted images allows single slices to be obtained within 1 s without the need for contrast or sedation. It must be noted that foetal MRI does not supplement ultrasound as a screening tool. Nor should MRI be performed in isolation for foetal diagnosis . The objectives of MRI are to confirm equivocal findings and to detect other anomalies that may be present, in particular intracranial extension .
Imaging combined with chorionic villous sampling and or amniocentesis will allow the clinicians involved to provide the family with a wealth of information. This will help to empower the family and allow an informed discussion regarding the details of the delivery, allay any concerns, provide genetic counselling and discuss future surgery. In the present case the family were committed to the pregnancy but declined chorionic villous sampling and amniocentesis.
Currently, the majority of craniofacial anomalies are repaired after birth. In cases of multiple or complex anomalies which compromise the viability of the foetus at the time of birth, post-natal procedures, which have been recently developed, can be deployed. One such procedure, ex-utero intrapartum treatment (EXIT), maintains feto-placental blood flow after caesarean section . Satisfactory blood gas analysis can be obtained in about 1 h allowing the establishment of a conventional surgical airway . Management of patients in this manner requires a great deal of planning and a well established and rehearsed team.
Nasal gliomas are rare lesions estimated to occur in 1 in 20,000–40,000 live births, the male to female ratio being 3:2 . These lesions are benign non-hereditary congenital midline malformations, composed of heterotopic masses of neuroglial tissue. Approximately 60% of the lesions are extranasal, 30% are intranasal and 10% have extranasal and intranasal components .
Congenital gliomas occur due to abnormal closure of the anterior fontanel at the junction between the nasal and frontal bones during embryonic development. This can cause incomplete separation of ectodermal and neuroectodermal elements. Nasal glioma develop if neuroglial tissue remnants persist extracranially following closure of the anterior fontanel. The differential diagnosis of nasal glioma includes encephalocele, teratoma, dacryocystocele, retinoblastoma and haemangioma.
Previous reported cases of gliomas have all been diagnosed after 21 weeks of gestation . Resection of the lesion was performed after 4 months of age without complication. In the present case, the authors detected the lesion at 20 weeks’ gestation and opted for surgical resection at 2 months of age in order to protect binocular visual development.
In conclusion, the maxillofacial surgeon is becoming increasing involved in the diagnosis and management of foetal anomalies. The technology used in foetal imaging and their capabilities are expanding at a rapid rate, offering new opportunities in foetal care. This care package also includes the education and counselling of the family involved. The maxillofacial surgeon is an important part of a comprehensive multidisciplinary team providing expertise for patients with a variety of facial anomalies and providing advice regarding the nature of the anomaly and its management.