Incidence of so-called in situ Neuroblastoma in the Fetal Adrenals

Abstract

Neuroblastic cell nests seen in infant adrenal gland are often called in situ neuroblastoma. The significance of these neuroblastic cell nests in adrenals of neonates is still in debate. It has been the mainpoint of discussion whether these neuroblastic cell nests could develop into clinical neuroblastoma, and if so, what would be chance? It was our purpose to examine the fetal adrenal glands to determine the incidence of neuroblastic cell nests in varying gestational periods. A total 113 pairs of adrenal from fetuses ranging from 10 to 42 weeks and 13 neonates within one week of age were removed at autopsy and serially sectioned. The following results were obtained: l. Neuroblastic cell nests were fairly commonly seen in fetal adrenal glands, being 37. 2% in overall incidence. 2. The incidence of neuroblastic cell nests in fetal adrenals was remarkably different by different gestational periods. In general the earlier the gestational age, more often these cell nests were observed. Full term fetuses and neonates were almost completely devoid of neuroblastic cell nests in adrenal glands. 3. Although cytologically neuroblastic cell nests seen in this study are indistinguishable from clinical neuroblastoma, these cell nests showed a tendency of regression in terms of frequency of finding neuroblastic cell nests as fetal age advances. 4. Neuroblastic cell nests seen in fetal adrenal do not appear to be normal embryological phenomenon of adrenal medullary maturation