Adrenal mass with liver metastases at the age of 2 months - compatible with neonatal neuroblastoma, stage 4S.

Liver, core biopsy:

Cores of liver tissue massively infiltrated by a small blue cell tumor, showing morphological and immunophenotypical features consistent with a poorly differentiated neuroblastoma, Schwannian stroma poor.

The MKI (mitotic karyorrhexis index) is low (<2% or <100/5000 cells). On immunostains, the tumor cells are positive for CD56, synaptophysin and focally/weakly positive for chromogranin and they are negative for myogenin, CD99, and MNF116 cytokeratin. The betacatenin and FLI1 are also positive in the tumor cells.

FISH study unavailable.