Prenatally detected cystic adrenal mass associated with Beckwith-Wiedemann syndrome.

We report a case of a right-sided cystic adrenal mass, detected after the 21st week of gestation, associated with fetal macrosomia. The diagnosis of Beckwith-Wiedemann syndrome was evoked. Prenatal sonography and magnetic resonance imaging did not allow establishing the origin of the suprarenal mass. The differential diagnosis of cystic neuroblastoma, pseudocystic adrenal haemorrhage, and adrenocortical macrocysts was discussed. A laparotomy was performed 2 weeks after birth due to the increasing size of the tumour and due to its possible malignant origin. Histological findings were haemorrhagic lesions without evidence of malignancy and adrenal cortical cytomegaly. The diagnosis of an adrenocortical macrocyst component of Beckwith-Wiedemann syndrome was established.