What is sacrococcygeal teratoma (SCT)?

Sacrococcygeal teratoma (SCT) is a tumor that develops before birth and grows from a baby's coccyx — more commonly known as the tailbone. It is the most common tumor found in newborns.

The tumor is usually covered with skin, but may be covered by a thin, transparent tissue called a membrane. Most tumors have many blood vessels coming through them. They come in many different sizes, and sometimes they may grow outward from the back or toward your child's stomach.

SCT tumors are categorized according to their location and severity:

• Type I tumors are external (outside the body) tumors and are attached to the tailbone.
• Type II tumors have both internal (inside the body) and external parts.
• Type III tumors can be seen from the outside, but most of the tumor is inside your child's abdomen.
• Type IV tumors, the most serious tumors, can't been seen from the outside. They are inside the body at the tailbone level.

The signs and symptoms of sacrococcygeal teratoma depend largely on the size and location of the tumor. Some tumors can be diagnosed by ultrasound before your child is born.

If you are referred to the Center for Fetal Diagnosis and Treatment (CFDT) at Children’s Hospital of Philadelphia (CHOP), you will undergo a thorough daylong evaluation to confirm the diagnosis of sacrococcygeal teratoma.

Risks and complications

When a prenatally diagnosed SCT is associated with fetal hydrops, the tumor can become life-threatening to both mother and baby.

In severe cases, the tumor "steals" blood from fetal circulation, causing the heart to work extra hard and making cardiac failure possible. Cardiac failure exhibits as fetal hydrops, a massive accumulation of fluid in the body of the fetus.

For the mother, there is the risk of “maternal mirror syndrome” in which the mom’s condition parallels that of the sick fetus. When fetal hydrops is present, the mother may "mirror" the sick fetus, becoming ill with signs of preeclampsia.

Monitoring and delivery

If your baby’s condition is stable with no high output cardiac failure (fetal hydrops), your pregnancy will be followed with regular ultrasound monitoring. If the SCT is small, a vaginal delivery at term may be planned.

If the SCT is large or if there is an excess of amniotic fluid (polyhydramnios), an early cesarean section is planned to avoid tumor rupture as well as the risks of preterm labor and premature delivery.

If fetal hydrops develops, you may be a candidate for fetal surgery.

Treatment of sacrococcygeal teratoma

Treatment for SCT involves surgery to remove the tumor. Depending on the diagnosis and severity of your child’s SCT, they may undergo fetal surgery to remove the SCT before birth, or they may have tumor resection surgery after they're born.

Fetal surgery is only indicated when fetal hydrops is present, putting your child’s life at risk.

During the surgery, your child’s pediatric surgeon will remove both the tumor and your child's tailbone. The tailbone is removed because the tumor grows from it, and if it's not removed, the tumor may grow back.