Clinical and perinatal sonographic features of congenital adrenal cystic neuroblastoma: a case report with review of the literature.

Cystic formation in association with adrenal neuroblastoma may be related to hemorrhage and necrosis of the tumor. We present an unusual case of congenital cystic fetal neuroblastoma of the right adrenal gland detected at 37 weeks' gestation which evolved into a complex echogenic mass 6 weeks after birth. Surgical exploration revealed a 3.5 x 3 x 3 cm right complex adrenal tumor which was resected. The infant did well 10 weeks after tumor resection. Typically adrenal hemorrhage may appear sonographically to be entirely echogenic, of mixed echogenicity, or anechoic when first imaged. Gradually, the texture of the hematoma will evolve and become more cystic and echolucent on follow-up ultrasound examinations. In contrast, our case of congenital adrenal cystic neuroblastoma became more complex after resolution of the hemorrhagic cyst. This case suggests that adrenal hemorrhagic and adrenal cystic neuroblastoma with a hemorrhagic cyst have different sonographic appearances. We suggest that additional imaging and surgical intervention should be considered whenever a cystic suprarenal mass becomes more complex after resolution and demonstrates no significant decrease in size in postnatal examinations.