CT Feature Analysis of Metanephric Adenoma

Objective: to analyze CT features and pathological features of metanephric adenoma in order to improve the preoperative diagnostic accuracy of MA. Data and methods: CT imaging data and pathological features of 5 patients with MA confirmed by surgical pathology was retrospectively analyzed, and MSCT manifestations and pathological features of MA were summarized in combination with literature. Results: all the 5 patients were female, aged 35-58 years, with an average age of 48 years. The lesions were almost round in shape with an average diameter of about 7.5cm. In 5 cases, the lesion protruded into the renal collecting system or/or the renal extrorenal system, and the surrounding structures were compressed and pushed, without local invasion or metastasis. The density of the lesions on plain scan was similar to that of renal parenchyma, but the density was not uniform. There was no bleeding, calcification or capsule in the lesions. In 5 cases, progressive heterogeneous enhancement was observed in the lesion on enhanced scan, mild enhancement was observed in the cortical phase, mild to moderate enhancement was observed in the parenchymal phase, and moderate enhancement was observed in the excretory phase. Low-density scar was observed in 2 cases. Pathology showed that the MA range and shape tended to be consistent with the section of the gross specimen, and was clearly demarcated from the surrounding renal tissue. MA cells were arranged in small glandular tubules with few cytoplasm and small nuclei. No mitotic figure and necrosis were observed. Immunohistochemical ki-67 (+, < 5%), -catenim (+), CK (+) and CK7 (+) were detected. Conclusion: the CT manifestations of MA have certain characteristics, combined with the occurrence of erythrocythemia in female patients, which is helpful to improve the preoperative diagnosis accuracy of MA.