RADIOLOGY: KIDNEY: Case# 34025: LARGE LEFT PERINEPHRIC HEMATOMA; BILATERAL ATROPHIC KIDNEYS. The patient is a 69 year old female with chronic renal failure on hemodialysis. The patient present with left back pain. 1. Large left perinephric hematoma. An underlying renal lesion is not clearly identified but is not excluded on this examination. A follow up examination is recommended following resolution of the hematoma to evaluate for an underlying renal lesion such as renal cell carcinoma, angiomyolipoma, or other underlying neoplasm. 2. Indeterminate lesion in the lower pole of the right kidney which does not meet CT criteria for a simple cyst, but does not show clear enhancement (less than 10 HU). This lesion probably represents a complicated cyst but a neoplastic process cannot be completely excluded on this study. 3. Bilateral atrophic kidneys consistent with the patients chronic renal failure.