[Renal carcinoma presenting as a multilocular cyst].

Although it is not uncommon to find small foci of cystic degeneration in renal adenocarcinoma, it is uncommon to find these so extensive as to permit a preoperative diagnosis of multilocular cyst as in the present case. Several etiopathogenic mechanisms have been described. In the present case, the underlying mechanisms are likely to be tumor necrosis and intrinsic multilocular cystic growth. Arteriography is not the best diagnostic method and there are doubts as to the usefulness of punction aspiration. Prognosis remains unclear.