[Diagnosis of a cyst wall hypernephroma]

The article reports on a 56-year old patient with the very rare preoperative diagnosis of a cyst wall hypernephroma. This diagnosis was confirmed both surgically and histopathologically. Diagnosis with the help of roentgenography showed that the diagnosis which had been suspected on the basis of selective arteriography, received a high measure of certainty by the additional use of non-invasive sonography and computerized tomography, thus finally justifying surgical approach to lay open the kidney.