Multilocular cystic nephroma. A diagnostic problem

: A multilocular cystic nephroma is described in a female patient diagnosed as having a mucinous cystadenocarcinoma of the left ovary, treated by surgery. It is presented as a mixed mass in the left kidney; image findings were specified with the new image diagnostic methods currently available, ultrasonography and computerized tomography. In the ultrasonographic study the mass is presented as an heterogenous image, with multiple anecogenic areas, separated by more ecogenic bands, situated mainly in the lower pole affecting all the cortical area and occasionally invading renal sinus. In the computerized tomography study a cystic mass is observed, with cysts of a different size that, after administering intravenous iodine, show a density increase in intercystical fibrous tracts. In cases with more complex image presentations, fine needle puncture is recommended, preferably in different areas in the mass in order to rule out the presence of malignant cells.