Contrast-Enhanced Ultrasound Features of Metanephric Adenoma: A Case Report and Literature Review

Metanephric adenoma (MA) is a rare primary renal epithelial tumor classified as a metanephric neoplasm. Its clinical symptoms and imaging features are non-specific, making preoperative diagnosis challenging and often leading to misdiagnosis as renal cell carcinoma (RCC). This report details the contrast-enhanced ultrasound (CEUS) findings of a 54-year-old male patient with a MA: 15 s after contrast agent injection, the lesion showed heterogeneous hypoenhancement, exhibiting progressive enhancement. The contrast agent began to fade at 50s, resulting in lower enhancement. Combined with a literature review, it aims to provide more comprehensive information for the imaging diagnosis of MA.