DIAGNOSTIC IMPLICATIONS OF N-MYC ONCOGENE EXPRESSION AND AMPLIFICATION IN PEDIAIRIC RENAL TUMORS

Abstract

Molecular and tissue culture techniques were used to characterize unusual bilateral renal tumors from a young boy. The left kidney demonstrated histopathologic and electron microscopic features of both neuroblastoma and Wilms' tumor. The contralateral kidney exhibited multiloculated cystic nephroma (MLCN). In vitro tissue culture of tumor cells induced neurite outgrowth. Hybridization experiments with an N-myc oncogene DNA probe revealed that the left renal neoplasm exhibited greater than ten-fold N-myc gene amplification in clvromosoma 1 DNA; N-myc was not expressed or amplified in the MLCN or in normal kidney tissue, however. While N-myc expression in RNA and histopathologic features could not clearly distinguish between Wilms' tumor and neuroblastoma, neurite outgrowth and gene amplification strongly suggested that this neoplasm would behave as an aggressive neuroblastoma. The diagnostic, prognostic and therapeutic implications of these findings will be discussed.