The natural history of neuroblastic cells in the fetal adrenal gland.

A study was made of neuroblastic nodules of the human adrenal gland in fetal life to determine their embryonic morphology and derivation. One hundred sixty-nine glands from 92 fetuses selected from 106 consecutively submitted fetuses formed the basis of this study. All adrenal glands examined contained neuroblastic nodules. They increased in number and maximum size with increasing age, peaked at 17 to 20 weeks gestational age, and regressed in the oldest fetuses. It is concluded that such neuroblastic nodules are an integral part of the normal morphogenesis of the adrenal gland. Their presence at birth and early infancy may represent a normal variation, and they do not necessarily constitute microscopic incipient malignancy.