PNET/Ewing’s sarcoma of the kidney: imaging findings in two cases

Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: A Rare and Lethal Entity

“…6,7 RADIOLOGIC FEATURES Imaging study findings in patients with ES/PNET include a large, ill-defined renal mass, often with heterogeneous contrast enhancement with intermixed areas of necrosis and hemorrhage (Figure, A). 3,5,6,8 Focal calcifications are occasionally seen. 3,9 The imaging features are in general nonspecific and the diagnosis, although rare, should be entertained whenever a young patient presents with a large renal mass.…”

The CT and US features of Ewing’s sarcoma/primary neuroectodermal tumor of the kidney: two case reports and review of literature

“…Third, the EWS/PNET is characterized with low or moderate enhancement, in both the arterial and venous phase enhancement images. 5 , 18 In our cases, low enhancement on the arterial phase and moderate enhancement on the venous phase were presented. Unlike large conventional RCCs, high enhancement on the arterial phase and low enhancement on the venous phase were presented.…”

“…Second, it is the difference in the pattern of the necrosis, hemorrhage, and cystic ingredient of the mass. 5 Advanced RCCs usually present central necrosis or hemorrhage, whereas EWS/PNETs are characterized by the multifocal or pervasive necrosis and hemorrhage. 18 Both the tumors consisted of solid components with hemorrhagic, cystic, and necrotic areas, resulting in heterogeneous attenuation numbers on unenhanced and contrast-enhanced CT scans ( Figures 1C and 2B ) and heterogeneous echoic to the adjacent renal parenchyma on US.…”

Unilateral Renal Primitive Neuroectodermal Tumor (PNET)

“…The most common clinical presentation is a vague pain in the flank. Imaging findings, such as huge renal mass (more than 10 cm in diameter) is prevalent (6,7,11). As the tumor is highly aggressive, it is often diagnosed at an advanced stage with distant metastasis, with lung being one of the most common sites (4,12,13).…”