Metanephric adenoma (MA) was first identified in 1979 and has been subsequently classified within the group of metanephric tumours, which comprise MAs, metanephric adenofibromas and metanephric stromal tumours. 1 The wide use of ultrasound, CT and MRI has led to an increase of incidentally discovered renal masses, including benign and malignant renal tumours. However, there are no unique and reliable radiological features for the differentiation of MA from renal cell carcinoma (RCC) and other benign renal tumours except for angioleiomyolipoma. There are no well-admitted criteria so this makes a diagnosis difficult; therefore, we performed the investigation focusing on CT imaging characteristics and corresponding pathological findings in order to establish CT diagnostic criteria of MA as the reference standard.
METHODS AND MATERIALS
Design and patientsThe clinical and radiological data were retrieved from archival files and were retrospectively analysed. Our institutional review board of The Second Hospital of Tianjin Medical University and Tianjin Union Medicine Center approved this study and waived the informed consent requirement. Data collected included age, gender, clinical presentation, preoperative tumour characteristics (size, location, diameter, nearness to collecting system, growth pattern etc) and final pathological findings. In total, 18 patients (9 males and 9 females; mean age, 50 years; range, 18-66 years) between