Endodermal Sinus Tumor Arising from Resected Benign Cystic Sacrococcygeal Teratoma

ABSTRACT

Endodermal sinus tumors are an uncommon malignancy in children and occur most often in the gonads and sacrococcygeal region. In these locations, thy are found as primary tumors ; in teratoma they form part of the malignant component. We present CT and MR imaging findings in two cases of endodermal sinus tumor occurring after the resection of a mature benign cystic sacrococcygeal teratoma during the neonatal period. Awareness of the transformation of a benign cystic teratoma to a different type of malignant germ cell tumor may be helpful in the evaluation of sacrococcygeal masses.