Characterization of karyotypic events and evolution in neuroblastoma.

Background: Neuroblastoma (NB) is cytogenetically characterized by a number of non-random events. However, knowledge is limited concerning the timing of occurrence and inter-action of many of these events.

Methods: Karyotypic patterns were obtained from a study group of 49 NB tumors that had been analyzed by conventional cytogenetics combined with FISH and in some instances SKY.

Results: All chromosomes were involved in a numerical and structural aberration in at least one tumor. There was a positive correlation between the occurrence of MYCN and del(1p) and between del(1p) and 17q. Aberrations involving chromosomes X, 3, 19, and del(1p) could be considered early events, whereas those involving chromosomes 9, 13, 15, 18, 20, and 21 were often late events.

Conclusions: This study suggests that the karyotypic patterns characterizing NB are complex. There are aberrations that can be grouped into early or late karyotypic events, but others, such as gain of 17q, are variable.