Mesoblastic nephroma fetal ultrasound
the most common fetal renal tumor, it is rarely detected before the mid-pregnancy anomaly scan (18–22 weeks) and is most frequently identified in the third trimester. MDPIMDPI +2Typical Ultrasound FindingsMass Characteristics: A large, unilateral, solid renal mass that is usually well-demarcated. Its echogenicity often resembles normal liver or renal parenchyma, which can make early detection difficult.The “Ring Sign”: A series of concentric hyperechoic and hypoechoic rings, highly characteristic of the classic subtype.Vascularity: Color Doppler often reveals high vascularization, sometimes showing a “vascular ring” around the tumor border or a large feeding vessel entering the mass.Heterogeneity: Complex areas with cystic spaces or septae may indicate hemorrhage or necrosis, features more common in the cellular variant.Prenatal diagnosis of CMN is often triggered by secondary signs rather than the mass itself:

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