The prognostic significance of Shimada classification in neuroblastic tumors In our study 54 cases of neuroblastoma diagnosed between 1977-1992 at our department were reevaluated according to Shimada classification. In the prognostic groups, distinguished according to histopathologic features, age and mitotic activity, the survival rates were 85.7% in favorable group and 3% in unfavorable group (p<0,001). We assessed interobserver concordance in this classification; the agreement rate was 96.3% in histologic grouping and 100% in prognostic grouping.