[Peripelvic cyst of the kidney]

There is discussion of a peripylonic cyst of the kidney as a very rare disease difficult to diagnose before operation. A cyst is most frequently as an expansive kidney process i.e. kidney tumor. Demonstrating the diagnostic procedures, the authors, by presentation of one of 3 cases, evaluate the value of each procedure separately and stress that the echotomographic procedure is the most reliable in the estimating of the parenchimal structure of the expansive process. However, an absolutely exact preoperative diagnosis is not yet possible, and remains to be established on the basis of the kidney changes in the course of the operation. The authors point out that the exact nature of disease in all their 3 cases was established only by operation.