Pseudotumor renal after partial nephrectomy with the use of surgical gelatin sponge

After renal parenchymal sparing surgery, with the use of surgical gelatin sponge, residual defects may persist on imaging studies at the sites of resection. These "pseudotumors" may lead to confusion as to whether a lesion was removed or has recurred. These lesions usually resolve within a year. We report a case of pseudotumor renal parenchymal sparing surgery in a 69 year old man, with resolution of the lesion 8 months after surgery.