Germ cell neoplasms of sacrococcygeal region

Thirty-two sacrococcygeal neoplasms of germ cell origin were assessed with respect to pathology and natural history. There were 20 mature teratomas, four immature teratomas, one embryonal carcinoma and seven mixed teratomatous neoplasms (teratocarcinomas). All but four neoplasms occurred in infants aged 2 years or younger and 23 of these had visible tumor masses at birth. Only one neoplasm which was present at birth as a visible mass recurred metastasized and caused death. Neoplasms that made their appearance sometime after birth were more frequently malignant. Seventy-eight per cent of the neoplasms occurred in females. The histologic patterns of growth in these germ cell neoplasms were the same as those encountered in the gonads with the exception that no germinomatous or choriocarcinomatous elements were found. Thirty-eight per cent of the tumors were histologically malignant although not all behaved so clinically. All mature and immature teratomas were clinically benign. Six of seven teratocarcinomas recurred, metastasized and caused the patients' deaths. The one embryonal carcinoma behaved in a very aggressive manner and caused death of the patient 2 months after diagnosis.