Postnatal management of cystic neuroblastoma.

Cystic adrenal neuroblastoma (NB) is highly unusual. We report two cases of cystic NB, detected antenatally and emphasize postnatal strategy management. Case 1: a right cystic mass was detected in a foetus in the 34th week of pregnancy, and checked as the same in the 36th week. Postnatal ultrasonography confirmed the presence of a growing adrenal cystic mass. MRI and MIBG scintigraphy suggested an isolated adrenal tumour, without catecholamine secretion. Surgical resection was decided upon and pathological examination confirmed the diagnosis of cystic NB. Follow-up found a recurrence at 10 months and the patient underwent excision after chemotherapy. Histology confirmed the metastatic origin from NB. Case 2: a right adrenal cystic mass was detected during pregnancy, with no regression of tumour size on postnatal US. MRI, MIBG scintigraphy, and catechol plasma and urinalysis led to the conclusion of an isolated non-secreting lesion. A right adrenalectomy was performed at 1 month. Pathologic examination diagnosed a cystic NB. We would suggest serial US examinations and early removal of any cystic mass with characteristic US signs (thick complex wall) or without regression on one month follow-up. Prenatal diagnosis may provide the best chances for neonatal excision and good prognosis.