We analyzed the amplification of the N-myc oncogene in 72 neuroblastoma patients. Tumor staging of these patients revealed 9 cases of stage I, 16 cases of stage II, 19 cases of stage III, 19 cases of stage IV A, 5 cases of stage IV B, and 4 cases of stage IV S. In our series, we found an interesting case of amplified change in the N-myc oncogene at the site of tumor origin and in the metastatic regions. We suspect this was due to a decrease in tumor cells caused by intensive chemotherapy before surgery. In the analysis of N-myc oncogene amplification in resected specimens it is important to examine the tumor cells microscopically.
