[Multilocular cystic renal cell carcinoma: our experience]

Multilocular cystic renal cell carcinoma is now recognized as an independent pattern by WHO; it is a rare malignancy with a predominantly cystic growth, characterized by very low oncologic evolution and then susceptible to conservative treatment. In the kidney cystic masses of different origin may arise, i.e. due to malformation, acquired disease or tumor. Renal neoplastic lesions may have a cystic or pseudocystic component. There are also four types of neoplasm with a predominantly cystic growth, including the multilocular cystic carcinoma, which are macroscopically very similar and impossible to differentiate through diagnostic pre-operative images. The Authors present four cases of multilocular cystic renal cell carcinoma diagnosed in the 2000-2007 period, with special reference to diagnostic difficulties and to pre- and intra-operative features of the neoplasm. In conclusion, the extemporaneous histological preoperative diagnosis of multilocular cystic renal cell carcinoma is not possible because it requires extensive sampling; furthermore, the final histological diagnosis sometimes needs particular immunohistochemical procedures to be confirmed.