Primary Ewing sarcoma of the kidney mimicking cystic papillary renal cell carcinoma in an older patient: A case report

Figure 1 Initial ultrasound and abdominal computed tomography scan of the right kidney. A: An 11 cm × 10 cm cystic lesion is noted in the right kidney with a 3.2 cm solid component on ultrasound B-mode; B: Increased vascularity is seen in the solid component on color doppler mode; C: A pre-contrast phase axial computed tomography (CT) shows a cystic lesion with a mass at the posterior-lateral aspect of the right kidney interpolar region-lower pole. A subtle high-attenuation area is seen in the cystic lesion, suggesting hemorrhage; D and E: Corticomedullary and excretory phase axial CT shows progressive enhancement of the mass (pre-contrast phase: 40 HU, corticomedullary phase: 70 HU, excretory phase: 80 HU) and a suspiciously indistinct margin (orange arrows) and invasion of the sinus; F: Corticomedullary phase coronal CT scan shows an irregular enhancing mass in a lesion with indistinct margins (orange arrow).