POOR OUTCOME IN PATIENTS WITH ADVANCED-STAGE NEUROBLASTOMA AND COINCIDENT OPSOMYOCLONUS SYNDROME

Background. Most patients with neuroblastoma who present with opsomyoc lonus have a good prognosis. Neuroblastomas from such patients have be en reported to contain a single copy of the N-myc gene. The authors de scribe three cases of patients with advanced neuroblastoma with opsomy oclonus, which had poor outcomes despite multimodal therapy. Methods. Amplification and expression of the N-myc gene were examined in these three primary tumors using Southern and Northern blot analyses. Then, flow cytometric analysis of the cellular DNA contents of these tumors was performed. Results. N-myc amplification was observed in two tumors and N-myc RNA overexpression was observed in all three. Analysis of t he cellular DNA contents of the tissue specimens revealed hyperdiploid y in all three tumors; one had a triploid index and the other two had hypotetraploid indexes. Conclusions. These findings suggest that a poo r outcome for patients with opsomyoclonus may be associated with N-myc gene activation (amplification and/or overexpression) and that a hype rdiploid tumor is not always associated with a good prognosis.