hypersecretion of fetal aldosterone. Prenatal differential diagnoses of fetal abdominal tumors include different tumors of renal origin, sub-diaphragmatic extralobar pulmonary sequestration, alimentary tract duplications, hepatic, choledochal, ovarian, or enteric cysts, renal vein thrombosis and retroperitoneal teratoma. In the case presented, a fast growing fetal abdominal tumor was observed at the end of 27th week of gestation during regular sonographic examination. All abdominal organs appeared normal on conventional 2D sonography and multiplanar view with 3D ultrasound technique. Expectant management was choosen for further pregnancy surveillance, based on the normal fetal growth and normal sonographic feature of all other organs. Serial ultrasound examinations were performed until fetal hydrops with polyhydramnion developed at 32 weeks of gestation. Neuroblastoma should always be considered as a differential diagnosis when a tumorous mass is depicted within the fetal abdomen. An expectant management is recommended for pregnancy surveillance. Postnatal prognosis is based on the gestational age at presentation and the stage of the tumor.