Multifocal neuroblastoma

Pediatric imaging of neuroblastoma-From classic to atypical

“…Multifocal primary NB is rare, but due to improvements in both our understanding and diagnosis of this disease, the incidence may increase [11,12]. Of note, although most NB is sporadic, multifocal primary NB is most often familial [13].…”

“…Of note, although most NB is sporadic, multifocal primary NB is most often familial [13]. It is important to distinguish between multifocal primary NB and metastatic NB because multifocal primary NB is associated with more favourable biological features, and aggressive treatment can be avoided [11,12]. Indeed, multifocal NB might regress without any treatment [11].…”

“…Indeed, multifocal NB might regress without any treatment [11]. Imaging findings that favor the diagnosis of multifocal primary NB over metastatic NB, are tumours on opposite sides of the body without distant lymph node, and bone or bone marrow metastases (Figure 4) [12]. Interestingly, it is thought that bilateral adrenal NB and stage 4S NB (similar to INRGSS stage MS), might actually be multifocal primary NB [11].…”

Coexistence of MYCN‐activating mutation and amplification in a patient with neuroblastoma

“…Chen et al8 reported that the amplification level of the rearranged MYCN gene was lower than that of the wildtype MYCN gene, indicating that the rearrangement occurred after initial MYCN gene amplification. In contrast, Hiyama et al9 reported that the rearranged MYCN gene was detected in primary tumor and lymph node metastasis, whereas the rearranged MYCN gene was amplified to the same degree as the wild-type MYCN. This indicated that the rearrangement of MYCN gene occurred before the initial MYCN gene amplification.…”

“…If the mutation had occurred before amplification, all amplified MYCN would be mutated; hence, the MYCN mutation must have occurred after MYCN amplification during tumorigenesis. Although the coexistence of MYCN mutation and amplification has not been previously reported, Chen et al8 and Hiyama et al9 reported the coexistence of MYCN rearrangement and amplification. Chen et al8 reported that the amplification level of the rearranged MYCN gene was lower than that of the wildtype MYCN gene, indicating that the rearrangement occurred after initial MYCN gene amplification.…”