[Multilocular cystic nephroma. A diagnostic and therapeutic challenge. Report of two cases].

Objectives: Multilocular cystic nephroma is a rare benign entity grouped among the cystic non genetic diseases, which usually presents with a clinical picture and radiological features indistinguishable from malignant neoplasias, making impossible to rule out malignancy preoperatively.
Methods: We report two cases of multilocular cystic nephroma which were treated with different surgical attitudes despite their clinical and radiological similarities, because on the second case intraoperative pathologic study of the specimen was performed.
Results: The diagnosis of multilocular cystic nephroma was confirmed in both cases, with the difference that radical nephrectomy was performed in the first case whereas the intraoperative study of the tumor in the second allowed to perform tumorectomy with renal parenchyma preservation.
Conclusions: We consider that in the presence of a multiloculated renal mass of complex appearance and benign clinical behavior, the intraoperative study of the tumor will avoid performance of radical surgery.