The diagnostic value of alpha-fetoprotein in infants and children with teratomas: a questionnaire survey in Japan.

Serum alpha-fetoprotein (AFP) values in 61 infants and children with mature, immature, or malignant teratoma were analyzed in comparison with the normal ranges of AFP. AFP was within the normal ranges in 23 of 24 mature teratomas, and higher than the upper border of the normal ranges in 31 of 32 malignant teratomas. The number of immature teratomas studied here was very small. These results suggest that the diagnostic value of AFP would seem very high even in infancy and childhood, if data are compared with the normal ranges. This conclusion appears particularly noticeable because the authors had once made a preliminary report on this subject in which they concluded that the differentiation between benign and malignant teratoma by AFP would be impossible under the age of 2 mo.