[Renal cystadenoma in children. Apropos of 5 cases].

The multilocular renal cystadenoma is a benign, rather uncommon tumor occurring in childhood (one case for 40 Wilms tumors). The clinical pathological study of five cases and the review of cases published in the literature show that this tumor, like all cystadenomata, is constituted by isolated cysts lined with cubic epithelium and inserted into each other. These cysts are included into mature mesenchymatous tissue. The renal cystadenoma appears as a large, regular, spheric mass, sharply demarcated from the pelvic cavities and renal parenchyma. Its volume is the main clinical sign. Occasionally, angiographic and echographic investigations may provide additional useful data. In some cases, the renal cystadenoma may be difficult to distinguish from a well differenciated cystic nephroblastoma. The differential features are emphasized and discussed. The renal cystadenoma must be regarded as a hamartoma developed from some metanephrogenic blastematous areas excluded from the normal embryogenetic process. The term of renal cystadenoma emphasizes the neoplastic nature and the macroscopic appearance of this tumor and must be preferred to designate this lesion.