Disseminated congenital neuroblastoma involving the placenta.

Neuroblastoma, a tumor of primitive neuroectodermal cells, is one of the most common solid malignancies of neonates. Placental metastases have been described in rare cases of congenital neuroblastoma, usually in association with hydrops fetalis, placentomegaly, and widespread disease in the neonate. We report a case in which the unexpected diagnosis of neuroblastoma was made based on the postnatal finding of tumor emboli confined to fetal vessels of the placenta. Radiation and chemotherapy were given based on this diagnosis, obviating the need for an invasive diagnostic procedure.