Background/Aims MYCN proto-oncogene is located on chromosome 2p24. MYCN amplification is a poor prognostic factor in neuroblastoma. However, the role of germline MYCN copy number gain is unclear. It is unknown if it is a prerequisite for MYCN amplification or an independent event in neuroblastoma.

Methods Case report of perinatal neuroblastoma with a mosaic interstitial 2p duplication and literature review.

Results A 3.3 cm right suprarenal mass was noted in a 2 day old infant with bilateral postaxial polydactyly, syndactyly and bicuspid aortic valve. He was observed clinically until 3 weeks of age when he presented with increasing abdominal distension, prominent hepatomegaly, enlarging suprarenal mass, and marked elevation of urinary VMA/HVA levels. Diffuse liver MIBG avidity was noted. Emergent chemotherapy was started and he underwent decompressive laparotomy secondary to abdominal compartment syndrome. He is currently five months into therapy and doing well. aCGH performed on peripheral blood leukocytes showed mosaic interstitial duplication from 2p24.1 to 2p25.3 involving the MYCN gene which was confirmed by FISH. Tumor MYCN amplification status is unknown.

Conclusion Management of perinatal neuroblastoma includes close observation with therapeutic intervention reserved for advanced stage and/or clinical progression. Two of the five cases of neuroblastomas described in patients with dysmorphic features and a germline partial 2p duplication, were detected perinatally. All patients had an aggressive clinical course. In the subset of patients with perinatal neuroblastoma and multiple congenital anomalies, FISH or aCGH testing for partial 2p gain may identify those who may need more aggressive management.