CASE REPORT
Case 1. A 3-month-old female infant presented with left adrenal gland
origin NB, stage 4S. Her urine homovanillic acid (HVA) and
vanillylmandelic acid (VMA) levels were 6,612 μg/mg Cr (<18
µg/mg Cr) and 3,200 μg/mg Cr (<23 µg/mg Cr). Because the case
was complicated with inferior vena cava syndrome, irradiations to the
liver (1.5 G/dose, for 3 days) and one cycle of chemotherapy
(vincristine and cyclophosphamide) were administered prior to tumor
biopsy for avoiding any oncology emergency. The biopsy image of the
metastases of the liver after the irradiation showed that the NB was
poorly differentiated with intermediate MKI (192/5000). Histology data
after chemotherapy led to a classification of conventional NB as per
Suganuma classification, which is equivalent to FH of INPC (Fig. 1A).
DNA ploidy analysis showed that the tumor was diploid, and real time
polymerase chain reaction (RT-PCR) data showed that it harbored 20
copies of MYCN . MYCN -A was also detected by fluorescencein situ hybridization (FISH) (Fig. 1B). Immunohistochemical
staining with an anti-N-myc rabbit polyclonal antibody (Proteintech
Group, Rosemont, IL, USA) revealed that the tumor was negative for N-myc
(Fig. 1C). She received six cycles of chemotherapy (cisplatin,
vincristine, cyclophosphamide, and pirarubicin), underwent total
resection of the primary tumor and 13-cis-retinoic acid maintenance
therapy without autologous stem cell rescue and radiation therapy in the
tumor bed. She remained disease-free for the 74 months following tumor
resection.
Case 2. A 10-month-old male infant presented with left retroperitoneal
NB, stage 2B. Urine HVA and VMA levels were of 168.2 µg/mg Cr and 101.3
μg/mg Cr. The biopsy showed that the NB was poorly differentiated with a
low MKI (26/5000), fitting within the FH classification (Fig. 1D). The
tumor showed to be a mixture of diploid and hyperdiploid. Moreover, it
harbored 5.6 copies of MYCN , which was not considered to beMYCN -A but genetic gain.7 MYCN -A
detected by FISH (Fig. 1E) helped interpret the clinical data as a
discordance case. The tumor histology showed that the NB was a
conventional type as per the Suganuma classification, since N-myc
staining was negative (Fig. 1F). He received six cycles of chemotherapy
(cisplatin, carboplatin, etoposide, vincristine, cyclophosphamide, and
pirarubicin), underwent total resection of the primary tumor and
received 13-cis-retinoic acid maintenance therapy without autologous
stem cell rescue and radiation therapy. He remained disease-free for the
38 months following the tumor resection.