Pure cystic nephroblastoma of the ovary with a review of extrarenal Wilms'tumors

A second case of pure ovarian extrarenal Wilms' tumor (EWT) is presented. A clinical stage Ic tumor occurred in the right ovary of a 21-year-old femal e and corresponded to a 19-cm multilocular mass which histologically was a cystic, partially differentiated Wilms' tumor, closely resembling the highl y differentiated metanephric adenoma. This pattern is reported for the firs t time in an ectopic location. At the interface between epithelial nests an d ovarian tissue, plaques of alpha-inhibin positive cells were detected tha t corresponded to foci of peripheral stromal luteinization. Differential di agnosis with entities such as retiform Sertoli-Leydig cell tumors and with adenosarcoma should be made. The literature on EWT is also reviewed. HUM PA THOL 31:761-764. Copyright (C) 2000 by W.B. Saunders Company.