Extrarenal adult Wilms' tumor.

ABSTRACT

Extrarenal Wilms' tumor is a very rare disease, occurring mostly in children. Sixteen cases have been reported in the world medical literature. A case of retroperitoneal extrarenal Wilms' tumor is reported in a 36-year old white male and the literature reviewed. Pathologic examination revealed both undifferentiated renal blastoma plus differentiated areas containing immature tubules and glomeruli. No evidence of extrarenal teratomatous tissue was seen. Theories for the histogenesis of this rare tumor are discussed.