Fetal Giant Neck Masses
What is a fetal giant neck mass
Fetal giant neck masses such as cervical teratoma and lymphangioma can grow to such large proportions that the fetal airway becomes distorted and obstructed. In a small number of patients with cervical teratomas, the mass effect pulls the lungs into the apex of the chest and results in pulmonary hypoplasia, or underdeveloped lungs.
In addition to obstructing the airway, these fetal giant neck masses can compress the esophagus, resulting in polyhydramnios, which can lead to pregnancy complications and preterm labor. Unsuspected obstructive fetal giant neck masses often prove fatal because of an inability to secure an airway and ventilate the baby upon delivery, which results in hypoxia and acidosis. If the delay is longer than five minutes, anoxic brain injury may occur. This illustrates the importance of prenatal diagnosis and delivery planning, since most children with a fetal giant neck mass have an isolated anomaly and do well after postnatal resection.
Unfortunately, we do not know what causes giant neck masses. However, we do know that fetal giant neck masses are not a genetic problem and, therefore, do not run in families. Your next child faces no greater or lesser risk of developing this problem than any other child.
Testing and diagnosis
Giant neck masses are typically detected by ultrasound. When patients are referred to the Center for Fetal Diagnosis and Treatment with a diagnosis of a fetal neck mass, an in-depth evaluation is performed by our specialized multidisciplinary team to confirm the diagnosis. Mothers undergo a level II ultrasound detailing fetal growth and development as well as anatomy, with concentration directed toward the neck mass. A complete obstetric history, physical and genetic evaluation is performed to rule out other problems with the pregnancy.
It is important to identify the type of neck mass and its relationship to adjacent structures. If the neck mass obstructs the esophagus, your baby is unable to swallow the amniotic fluid that surrounds her in the womb. As a result, this fluid builds up to abnormally high levels — a condition known as polyhydramnios. If left untreated, the excess fluid can bring on preterm labor.
An ultrafast fetal MRI, performed without maternal sedation or fetal paralysis, is another advanced fetal imaging test that can help distinguish between the various types of neck masses. A fetal echocardiogram is performed to assess any structural abnormalities of the heart. After your evaluation, our team will meet with you to explain the diagnosis, discuss treatment options and answer your questions.
Monitoring and delivery
If the neck mass is small and does not compromise the airway, close ultrasound surveillance is warranted to follow the growth of the mass throughout the duration of your pregnancy.
For larger masses resulting in polyhydramnios, treatment options during pregnancy include bed rest, medication to decrease amniotic fluid, or regular procedures to remove excess fluid from the womb (amniocentesis). In amniocentesis, a local anesthetic is used to numb the skin on the abdomen, and a needle is inserted into the womb to remove some amniotic fluid. During the procedure, ultrasound is used to visualize the fetus, enabling your physician to choose a puncture site that is far away from the baby.
If the polyhydramnios persists and the mass continues to grow, your baby may be delivered via the EXIT procedure.
An EXIT procedure is a surgical procedure that is used to deliver babies who have airway compression due to cervical teratomas, cystic& hygromas, or blockage of the airway such as congenital high airway obstruction (CHAOS) syndrome. It is similar to a caesarean section, but there are some important differences.
We have adapted the EXIT procedure for the management of fetal giant neck mass and have performed more than 60 EXIT procedures to date. Close coordination between your surgeon and anesthesiologist minimizes the risks associated with the EXIT procedure.
Giant neck masses are typically surgically removed after birth. The EXIT procedure allows time to perform procedures commonly used to treat babies born with giant neck masses, such as direct laryngoscopy, bronchoscopy, tracheostomy, surfactant administration, cyst decompression and tumor resection. Some or all of these procedures may be required to secure the airway and provide adequate ventilation.
Some babies need temporary help with breathing and eating. The compression of the windpipe can cause it to become soft, making it prone to collapse. For this reason, a temporary tracheostomy is sometimes necessary to allow your baby to breathe normally until the trachea hardens. A tracheostomy is a surgical opening in the trachea (or “breathing tube”), which makes breathing easier.
In addition, some babies may need to be partially or totally fed using a tube that goes directly into the stomach. While your baby is still in the hospital, we will help you learn how to administer these tube feedings and to care for the tracheostomy at home. Home care professionals will also make home visits to monitor your baby's progress and assist with care.
Central to achieving an excellent outcome for babies prenatally diagnosed with a giant neck mass is the coordination of our experienced team of pediatric surgeons, fetal and maternal anesthesiologists, obstetricians, neonatologists and obstetrical, neonatal and operating room nurses.
During infancy, care focuses on ensuring that your baby can breathe and eat effectively. Long-term problems are not expected. However, children who have had a giant neck mass will receive long-term follow-up care at regular intervals because they are at higher risk for a re-growth of the mass.
Some cervical teratomas arise from the thyroid gland. After the surgery, your baby may need thyroid hormone supplements. Sometimes these supplements are only needed temporarily until the remaining thyroid grows back. Your baby's calcium level can also be affected by the cervical teratoma because of its effect on the parathyroid glands. As a result, babies with cervical teratoma occasionally need calcium supplements.