FIGURE 1 Ultrasonography of succinate dehydrogenase-deficient renal cell carcinoma. (A) Grayscale ultrasound showed that the cystic-solid mass was oval, well-defined, and approximately 41 mm×40 mm in size. (B) Color Doppler flow imaging showed that the solid component of the mass was isoechoic and approximately 16 mm×9 mm in size without any blood flow signals.