[Congenital fetal neuroblastoma].

Neuroblastoma are pediatric tumors of neural crest origin, most often localized in adrenal glands and infrequently congenital. We report two fetal cases found at autopsy, performed at 24 and 28 weeks of gestation, respectively. The 24 week old fetus did not show any malformation; systematic histological analysis found neuroblastoma cells in both the adrenal glands and the retroperitoneal fat tissue. The 28 week old fetus was hydropic and exhibited a nodule (3 cm) in the posterior mediastinum, next to the thoracic spinal cord. This tumor responded to a neuroblastoma associated with small metastatic foci in the adrenal glands, the liver and the frontal brain cortex. The placenta was abnormally heavy and showed hemorrhagic and necrotic areas. Microscopically plugged clumps of neuroblastoma cells were found inside fetal vessels. Immunohistochemistry was employed in both cases and the cells showed immunoreactivity for NSE, NB 84, chromogranin, synaptophysin and neurofilaments, while desmin, MIC 2, and protein S-100 were negative. Congenital neuroblastomas are rare and, to our knowledge this is the thirteenth report of congenital neuroblastoma associated with placental metastasis.