Ultrasound and CT features of atypical renal angiomyolipoma

Research purpose: investigation of the features of the ultrasonography and computed tomography (CT) image of the uncharacteristic renal angiomyolipomata (AML) and the analysis of the diagnostic efficacy of these radiologic means.
Materials and methods: the data of the radiologic checkup of 12 patients with verified AML were investigated. For all the patients, multihelical computed tomography (MHCT) and ultrasonography (US) including perioperative in 5 observations were performed. A comparative evaluation of the opportunities of the given radiomethods in diagnosing atypical AML is executed.
Results: when in preoperative observation, CT image of tumor of the all patients was not characteristic of AML. All the tumors were solid, roundish formations, mainly extrarenal, with a density conforming to soft tissues, and in the native phase of the study didn't practically differ from unaffected renal parenchyma. In intravenous contrast enhancement, the uneven accumulation of the contrast medium occurred, at that their heterogeneity became more apparent. Thus, according to CT data all the patients were diagnosed with renal cancer. At that, the US image of the 11 patients was typical of AML. According to histology of the operational material, a change in ratio of the structural components of the AML, favoring significant predominance of the smooth muscle component, was revealed in all the tumors.
Conclusions: If the smooth muscle component predominated in the structure of the renal AML, the atypical CT image may be a cause of diagnostic errors, specifically, renal cancer hyperdiagnostics. In these cases especially when planning organ-sparing surgeries, the one should consider that sonographic signs of the majority of such tumors remain characteristic of AML.