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Sacrococcygeal Teratoma (SCT)Learn More

• What is Sacrococcygeal Teratoma?
• What is the outcome for a fetus with Sacrococcygeal Teratoma?
• How serious is my fetus’s diaphragmatic hernia?

What is Sacrococcygeal Teratoma?

Sacrococcygeal teratoma (SCT) is an unusual tumor that, in the newborn, is located at the base of the tailbone (coccyx). This birth defect is more common in female than in male babies. Although the tumors can grow very large, they are usually not malignant (that is, cancerous). They can usually be cured by surgery after birth, but occasionally cause trouble before birth.

SCT is usually discovered either because a blood test done at 16 weeks shows a high alpha feto-protein amount, or because a sonogram is done because the uterus is larger than it should be. The increased size of the uterus is caused by extra amniotic fluid, called polyhydramnios. The diagnosis of SCT can be made by an ultrasound examination.

What is the outcome for a fetus with Sacrococcygeal Teratoma?

Most fetuses with sacrococcygeal teratoma do well with surgical treatment after birth. These tumors are generally not malignant. Babies with small tumors that can be removed along with the coccyx bone after birth can be expected to live normal lives, although they should be followed for development of tumors later in life, using a simple blood test for alpha feto-protein. Fetuses with larger tumors or tumors that go up inside the baby’s abdomen will require more complex surgery after birth, but in general do well. Again, they will have to be followed with blood tests for several years. Fetuses with very large tumors, which can reach the size of the fetus itself, pose a difficult problem both before and after birth.

We have found that those SCTs that are largely cystic (fluid-filled) generally do not cause a problem for the fetus. However, when the SCT is made up of mostly solid tissue and has a lot of blood flow in it, the fetus can suffer adverse effects. This is because the fetus’s heart has to pump not only to circulate blood to its body, but also to all the blood vessels of the tumor, which can be as big as the fetus. In essence, the heart is performing twice its normal amount of work. The amount of work the heart is doing can be measured by fetal echocardiography. This sensitive test can determine when the fetus is approaching heart failure.

Fetuses with large tumors and a great deal of blood flow to the tumor have to be followed closely for the development of hydrops or fetal heart failure which can forecast fetal death. If hydrops does not develop, these babies will require Cesarean-section delivery and extensive operation after birth. Most babies will do well once the tumor is completely removed. There can be long-term consequences which include the need to monitor (with blood tests) the development of a malignant tumor or difficulty with urination as a consequence of the surgical procedure. If hydrops does develop, usually in solid rapidly growing tumors, the fetus usually will not survive without immediate intervention before birth.

Maternal Mirror Syndrome

In cases with extreme fetal hydrops, the mother may be at risk for maternal mirror syndrome, which is a condition where the mother's condition mimics that of the sick fetus. Because of a hyperdynamic cardiovascular state, the mother develops symptoms that are similar to pre-eclampsia and may include vomiting, hypertension, peripheral edema, proteinuria and pulmonary edema. Despite resection of the anomaly, maternal mirror syndrome may still occur.

How serious is my fetus’s Sacrococcygeal Teratoma?

In order to determine the severity of your fetus's condition it is important to gather information from a variety of tests and determine if there are any additional problems. These tests along with expert guidance are important for you to make the best decision about the proper treatment.

This includes:

1. The type of defect—distinguishing it from other similar appearing problems.
2. The severity of the defect—is your fetus’s defect mild or severe.
3. Associated defects—is there another problem or a cluster of problems (syndrome).

The severity of sacrococcygeal teratoma is directly related to the size of the tumor and the amount of blood flow to the tumor. Both the size and the blood flow can now be accurately assessed by sonography and echocardiography. Small or medium-sized tumors without excessive blood flow will not cause a problem in the fetus. These babies should be followed with serial ultrasounds to make sure the tumor does not enlarge or the blood flow does not increase. They can be then delivered vaginally near term, and the tumor successfully taken care of after birth.

Very large tumors are prone to develop excessive blood flow, which causes heart failure in the fetus. Fortunately, this is easy to detect by sonography. These babies need to be closely followed for the development of excess fluid (link to new patient page) in the abdomen (ascites), in the chest (pleural effusion), in the pericardium (pericardial effusion), or under the skin (skin edema). It is the extra blood flowing to the tumor that strains the fetal heart enough to cause heart failure(hydrops).