Oncofetal antigens in sacrococcygeal teratomas.

Sacrococcygeal teratoma (SCT) is an uncommon tumor that primarily occurs in female infants. Histologic assessments of these neoplasms for immature neuro-epithelial elements and malignant germ cell components correlate with recurrence and metastases, respectively. In this report of 15 SCTs, in addition to routine histologic evaluation the tumors were studied for the presence of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), and human chorionic gonadotropin (HCG) by the immunoperoxidase method. Both CEA and AFP were commonly (82% and 53%) present in benign epithelium of these teratomas. In three cases, a germ cell component was identified in which two were focally positive for both CEA and AFP. Although presence of these antigens did not correlate with tumor grade, immunoperoxidase for oncofetal antigens may be useful in predicting which serum marker to measure in patients with suspected recurrent teratoma.