Increased numbers of argyrophilic nucleolar organizer regions between primary and metastatic sites predict tumor progression in stage IV and IV-S neuroblastoma.

Abstract

A silver colloid technique to determine nucleolar organizer region (AgNOR) number was used to study the proliferative activity of Stage IV-S neuroblastoma in which a spontaneous tumor regression is often observed. Primary regional lymph nodes and hepatic lesions from five children with Stage IV-S and five with Stage IV neuroblastoma were examined. Average AgNOR counts per tumor cell nucleus from all five children with Stage IV neuroblastoma were lowest in the primary lesions, intermediate in the metastatic regional lymph nodes, and highest in the distant metastases. However, in four Stage IV-S patients whose metastases later disappeared and showed no sign of recurrence, the average AgNOR number was similar in primary tumors and metastatic lesions. In the other patient with progressive metastases initially diagnosed as Stage IV-S, the data showed the same pattern as in Stage IV neuroblastoma. The unique AgNOR staining pattern may reflect the proliferative activity of Stage IV-S neuroblastoma. This method may provide further information to differentiate a subtype of metastatic neuroblastoma showing spontaneous tumor regression and/or favorable prognosis.