[Multilocular renal cyst in adults: a diagnosis by exclusion?].

The clinical and the gross and microscopic features of two multicystic masses in adult female patients are described. These met the Powell and Boggs and Kimelstiel criteria for multilocular renal cyst (MRC). MRC may be the common process and the gross expression of different disease entities with different biological significance which must be distinguished clinically and anatomopathologically. We present the data for differential diagnosis of conditions that may present as MRC: partially differentiated cystic nephroblastoma, mesoblastic congenital cystic nephroma, lymphangioma (more common in infants), cystic renal carcinoma and sarcoma, segmental polycystic kidney (more common in adults) and segmental renal dysplasia. The diagnosis of multilocular renal cyst should be made only after discarding the foregoing conditions.