Prenatally diagnosed cystic neuroblastoma: a report of two cases.

We report two cases of prenatally diagnosed cystic neuroblastoma (PDCN). In the first case, prenatal ultrasonography (US) at 33 weeks' gestation showed a 30 x 20 mm cyst at the upper pole of the right kidney. The size and content of the mass demonstrated no change during pregnancy. Postnatal US showed no change in the cystic mass 4 weeks after birth compared to the prenatal findings. The infant underwent total resection of the tumour at 28 days of age. In the second case, a left cystic mass measuring 50 x 40 mm was detected in a fetus in the 37th week of pregnancy. Postnatal US showed a cystic mass in the left adrenal gland. The US findings showed no change 18 days after birth and the infant underwent total resection of the tumour at 19 days of age. In both cases, pathological examination revealed a neuroblastoma and all of the biological prognostic factors were favourable. Surgical intervention was necessary for a final histological and biological diagnosis to be made. We recommend that prenatally suspected neuroblastomas should normally undergo surgical intervention, unless tumour size decreases within about 1 month after birth.