PREOPERATIVE DIAGNOSIS OF RENAL ANGIOMYOLIPOMA - FINE-NEEDLE ASPIRATION CYTOLOGY AND IMMUNOCYTOCHEMICAL CHARACTERIZATION

A preoperative diagnosis of renal angiomyolipoma (AML) is of great imp ortance for a correct management of these patients with this tumor. In fact when the lesion is small and asymptomatic a conservative approac h may be considered. We have evaluated the radiographic and fine needl e aspiration cytology (FNAB) findings in 8 cases of AML. In 3 cases bo th radiology and cytology were suggestive of carcinoma and thus the pa tients underwent surgery. In one case both techniques suggested AML bu t surgery was performed because the lesion was large and symptomatic. In 4 cases where both radiology and cytology suggested AML no surgery was performed. Follow-up data are consistent with the benign nature of the lesions. The immunocytochemical analysis of the FNAB with a panel of antibodies including keratin, vimentin, actin and HMB-45 was indic ative of AML in 7 of 8 cases, including 2 of the 3 cases misdiagnosed as carcinomas. The presence of HMB-45-positive perivascular epithelioi d cells in the FNABs was the most significant finding. It is concluded that immunocytochemical analysis of FNAB with this monoclonal antibod y panel can increase the accuracy of preoperative diagnosis of AML, an d allow consideration of a conservative approach in selected cases,