Two Cases of Neuroblastoma with Genotype–Phenotype Discordance:
Clinical Management According to Histological Subtype and N-myc
Expression
Abstract
MYCN-amplified neuroblastoma demonstrating favorable histology, which is
genotype–phenotype discordant, is extremely rare. This study reports
two cases of peripheral neuroblastic tumors with genotype–phenotype
discordance: a 3-month-old female and 10-month-old male patients with
stage 4S and 2B neuroblastoma, respectively, harboring
MYCN-amplification and favorable histology. Immunohistochemical staining
was negative for N-myc. Both patients were treated with conventional
chemotherapy and 13-cis-retinoic acid without autologous stem-cell
rescue, and have been disease-free for 74 and 38 months post-resection,
respectively. Nevertheless, chemotherapy could have been optimized on
the basis of histological features of the tumors, showing no expression
of N-myc.