Sun H, et al. - Among 3,799 male and 1,832 female patients with malignant teratoma, researchers calculated incidence trends, estimated prevalence, incidence rates, and frequency for gonadal and extra-gonadal tumors, adjusted for age. They also focused on the five-year observed, expected, and relative survival rates. Malignant teratomas showed two separate peaks: one peak composed of the extra-gonadal tumor was at under 1 year old, and another one composed of the gonadal tumor was at 20–24 for males and 10–34 for females. Significantly lower survival rates were revealed by the extra-gonadal tumor vs the gonadal. Overall, lots of differences were evident between gonadal and extra-gonadal malignant teratomas. Improved long-term survival rates might not be achieved with the help of chemotherapy.