US EPA

7107734 

Journal Article 

Focal versus diffuse anaplasia in wilms tumor - New definitions with prognostic significance - A report from the National Wilms Tumor Study Group 

Faria, P; Beckwith, JB; Mishra, K; Zuppan, C; Weeks, DA; Breslow, N; Green, DM; , 

1996 

Yes 

American Journal of Surgical Pathology
ISSN: 0147-5185
EISSN: 1532-0979 

LIPPINCOTT WILLIAMS & WILKINS 

PHILADELPHIA 

909-920 

8712292 

WOS:A1996UZ12600001 

Anaplasia, defined by the presence of extreme nuclear and mitotic atypia, is a potent marker of adverse prognosis in Wilms tumor (WT). Anaplastic WT cells apparently have increased resistance to therapy rather than increased aggressiveness. The distribution of anaplasia should therefore have critical prognostic relevance. The original definitions for focal anaplasia (FA) and diffuse anaplasia (DA) were based on quantitative rather than topographical criteria and lacked prognostic significance. A new definition was developed based on the distribution of anaplastic changes within the tumor: FA applies only to tumors with anaplasia confined to one or a few discrete loci within the primary tumor, with no anaplasia or marked nuclear atypia elsewhere. This revised definition was evaluated in 165 cases with anaplastic WT entered on the third and fourth National Wilms Tumor Study. Only three relapses and one death occurred among 39 cases with FA, regardless of tumor stage, a result comparable to that for nonanaplastic WT. Eight children with metastases at diagnosis and FA in the primary tumor were alive and free of relapse; 22 of 23 children with stage IV DA WT died of tumor. This new definition reinforces the importance of carefully documenting the exact site from which each tumor section is obtained.