Sacrococcygeal Teratoma
What is sacrococcygeal teratoma?
Sacrococcygeal (sae-crow-cox-i-gee-ul) teratoma (terr-uh-tome-uh) is the most common tumor found in newborns. "Sacro" refers to sacrum and "coccy" refers to coccyx. The sacrum is a curved triangular bone at the bottom end of the vertebral column or backbones, just before the coccyx. The last bone of the vertebral column (also known as the "tail bone") is the coccyx. Sacrococcygeal identifies the location. Teratoma refers to the type of tissues that makes up these growths. They are comprised of chaotically arranged tissues of all types (fat, bone, nerves, etc) that are found in an area that they are not normally found. Sacrococcygeal teratoma (SCT) is rare, occurring in 1 in 35,000 to 40,000 live births. It is four times more common in females than males. The cause is not known. One theory is it is a failed twinning attempt. Another is it is a growth from an abnormally placed set of germ or stem cells.
Sacrococcygeal teratomas have been classified by the amount of the tumor that is outside the body. There are four classification groups:
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Type I is completely external, evident at birth, and more easily resected or surgically removed. Type I does not typically spread.
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Type II has external and internal components. The internal portion is confined to the pelvic region. This type will spread in about 6 percent of cases.
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Type III also has external and internal components but the internal portion extends into the abdominal area. These types, II and III, are also evident at birth but the resection may be more difficult requiring access both from the back of the baby and from the front. Type III will spread in about 20 of cases.
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Type IV is completely internal. For this reason it may go undiagnosed for some time. Later, symptoms may develop that warrant an investigation and at this time the diagnosis is made. This type will spread in about 8 percent of cases.
Malignancy is not a primary cause of death for these infants, however. Other complications for SCT include hemorrhage within the tumor, development of hydrops and risk of preterm labor due to the size of the tumor and/or polyhydramnios (high volume of amniotic fluid). Approximately 11 to 38 percent of fetuses with an SCT will have other anomalies or birth defects. These associated defects increase the mortality rate as well. Sacrococcygeal teratomas can be quite large. Many are approximately the size of the unborn baby. Some of the SCTs are cyst-type tumors, meaning they are filled with fluid. Others are solid tumors that may have a significant amount of blood flow through them. The most common type of SCT is a combination of both solid and cystic.
The babies with large solid tumors are more prone to develop hydrops. This is, however, a small percentage of babies with SCT (less than 20 percent). Hydrops is an abnormal accumulation of fluid in two or more areas of the body. Some of the more common areas can include fluid in the abdomen (ascites), fluid around the lungs (pleural effusion), fluid around the heart (pericardial effusion), or extra fluid under the skin (anasarca) or scalp. If hydrops develops after 30 weeks' gestation, the mortality rate is approximately 25 percent. If, however, the hydrops develops before 30 weeks' gestation, the mortality rate is more than 90 percent. These babies may become candidates for fetal intervention if hydrops does develop early. This means some form of treatment may be available for the baby before it is born.
Prenatal diagnosis of sacrococcygeal teratoma:
Sacrococcygeal teratomas are most frequently diagnosed by routine ultrasound or ultrasound done for uterine size larger than gestational dates. Approximately 60 percent are diagnosed via prenatal ultrasound. As ultrasounds are becoming a normal part of routine prenatal care, this number is increasing. These babies need to be followed closely throughout the remainder of the pregnancy. Serial ultrasounds are recommended to observe and assess SCT growth, amniotic fluid volume, fetal well-being and for early evidence of hydrops. Serial echocardiogram or ultrasound of the heart is also recommended to assess for early signs of heart failure due to the perfusion required by a large solid SCT. Fetal MRI may be indicated to better assess the vascularity of the tumor. Your obstetrician will most likely refer you to a specialist that handles high-risk pregnancies. These doctors are called perinatologists. A pediatric cardiologist will also be involved to perform the serial fetal echocardiograms.
How does sacrococcygeal teratoma affect my baby?
Babies with SCT will normally do very well, however, they are at risk for preterm labor. This is partly due to the size of the teratoma. It is similar to the risk for a woman who is pregnant with twins. These pregnancies can also be complicated with an increased volume of amniotic fluid, which also carries with it an increased risk for preterm labor. The fetus is at risk for developing hydrops and/or heart failure, which will change the prognosis and chance of survival, especially if hydrops develops before 30 weeks' gestation. SCTs are sometimes associated with maternal complications such as preeclampsia or mirror syndrome, especially if hydrops develops. The mother will be monitored closely for early detection and treatment. The delivery method for these babies is determined by the size of the SCT. If it is small (less than 5-10 cm) the physician may consider vaginal delivery. However, there are other issues to weigh when vaginal delivery is considered. These can include but are not limited to the health of the mother and of the fetus, whether the mother has previously delivered vaginally and the size of that baby, as well as the position of the baby and whether the SCT is solid versus cystic. Otherwise, the choice method of delivery is Caesarean section. The surgical incision may need to be the classical type (from the belly button to the pubic bone) for ease of extracting the baby without injury to the SCT, which can lead to hemorrhage into the tumor. Hemorrhage into the tumor can seriously compromise the baby, even to the point of being life threatening.
How is sacrococcygeal teratoma treated?
These babies require careful handling to prevent injury to the SCT. Hemorrhage into the teratoma can be life threatening for the baby. Immediate access to veins is important if something happens with the SCT. In the umbilical cord are normally found two arteries and one vein. A special catheter will be passed into one of the arteries for arterial access. This is called an umbilical artery catheter or UAC. Through this line fluids and medication can be given, the blood pressure can be monitored continuously and blood can be drawn off for lab work. This way we do not have to do a needle stick to get blood samples for lab work. A special catheter may be passed through the vein in the umbilical cord also. This is called an umbilical venous catheter or UVC. Through this line medication and fluids can be given. Other IV lines may be started peripherally in the hands, arms, feet, lower leg or scalp.
Many times these babies will require special medicine to help their heart pump effectively enough to supply blood to the whole body as well as the SCT. Other medicines these babies may need are antibiotics, especially after surgery. Sometimes these babies will need to get blood transfusions. These blood transfusions may even be needed emergently in the delivery room if there is a severe hemorrhage of the tumor.
If the baby is born prematurely, there may be complications related to that. Because these babies may not eat for some time, special IV nutrition will be started to keep the baby well nourished. This IV solution has two components. One of the fluids is yellow and contains the vitamins, minerals, protein and sugar necessary for a complete diet. The other solution is milky white and contains the fats.
The baby will be given some time to adjust to life outside the womb unless there is bleeding within the SCT or the SCT is not completely covered by skin, or there is some other complicating factor. Once the baby has been stabilized after delivery, an abdominal ultrasound prior to removal will help assess the SCT and determine how much is internal versus external. A CT or MRI scan may also be done prior to surgery for better assessment of the tumor.
Sometimes if an infant is born premature and has a large SCT that is compromising heart function, a large portion of the blood supply to the SCT will be tied off. This will usually result in more normal heart function. This is beneficial for the baby to get a more stable respiratory status before surgery is attempted.
What about after surgery?
The baby will need support with breathing during and after surgery. This means an endotracheal tube (ETT) is passed between the two vocal cords, into the windpipe. This tube is attached to a ventilator that can give the baby oxygen and help breathe for the baby. Because of the position of the ETT, the baby is unable to make any noise. The baby will be on medicine to keep him or her still so they don't damage the surgical site. The baby will also be on medicine to keep him or her free of post-operative pain. He or she also will continue on the IV nutrition so that their body is being nourished so that it can heal from surgery. These babies are also given antibiotics after surgery to prevent infections.
Will I be able to help care for my baby after surgery?
Yes! Please ask your baby's nurse about ways to interact with and care for your baby. If you had planned to breastfeed your baby, you can begin to pump your breeast milk while you are still in the hospital. A lactation consultant can assist in answering your questions. Your milk will be frozen and stored in the Neonatal Intensive Care Unit until your baby is ready for it. The NICU has breast pumps and private rooms available to you when you are visiting. You can bring in pictures, small toys, booties and blankets for your baby while he or she is in the NICU.
When can my baby go home?
Your baby will go home when he or she is healed from surgery, his or her respiratory status is stable and he or she is eating enough to maintain and gain weight. A full-term baby with an SCT will have an average hospital stay of two to four weeks. If the baby is premature, the stay will likely be longer. Prematurity is the leading cause of mortality for these babies.
What is my baby's long-term prognosis?
The long-term prognosis for babies diagnosed prenatally with a SCT is excellent. An important indicator of prognosis is the age at diagnosis and resection. The earlier the prenatal diagnosis, the poorer the prognosis, especially if the diagnosis is the result of an ultrasound for maternal issues (such as uterine size larger that expected for gestational age). Cystic tumors carry a better prognosis also because they are less likely to hemorrhage or have heart failure complications such as hydrops. There are risks that can compromise these babies before and after birth. The two major complications that endanger these babies are difficulties with the resection and hemorrhage of the tumor. With resection, it is recommended that the coccyx be removed along with the SCT to prevent recurrence, the most likely complication. The risk of reoccurrence when the coccyx is not removed is 35 to 40 percent. |
