Neuroblastoma has several characteristics that differentiate it from other adult
malignancies. The ploidy pattern of
neuroblastoma has been shown to be related to prognosis. Specifically,
a DNA diploidy pattern is associated with a poorer outcome, and an
aneuploidy pattern is associated with a better outcome. A
tetraploidy pattern has also been identified; however, there is little information regarding this pattern. To examine the properties of
neuroblastoma according to these
DNA ploidy patterns, the authors performed flow cytometric analysis (retrospectively) for 61
neuroblastoma cases, using
paraffin-embedded tissues. Fifty-six of the cases had analyzable results. Calculated
DNA indices (DI) ranged from 1.0 to 2.30. The 56 cases were divided into three groups according to DI: diploid (DI = 1.0 to 1.17, n = 19),
aneuploid (DI = 1.25 to 1.75, n = 26), and
tetraploid (DI = 1.81 to 2.30, n = 11) groups. Compared with the
aneuploid group, the diploid group had a stronger correlation with older patient age (> or = 1 year) (P < .01), more advanced clinical stage (III, IV) (P < .01), and poorer prognosis (P < .001). The
tetraploid group had properties that were statistically similar to those of the diploid group (P < .05, P < .05, P < .001, respectively). These findings indicate that a subset of
DNA tetraploid is present in
neuroblastoma, and this subset, which may have clinical and
biological characteristics similar to those of the
DNA diploid group, should be distinguished from
DNA aneuploidy.