Fetal tumors are very rare. Sacrococcygeal tumors, the most common type of fetal tumor, are generally not malignant in neonates and have a good prognosis provided they can be successfully removed.
Sacrococcygeal teratoma (SCT) is a benign tumor that arises from the tip of the coccyx (tail bone). It can become so enormous during pregnancy that the fetus can die from intrauterine cardiovascular failure. In such cases the only possible treatment is prenatal removal of the tumor.