RADIOLOGY: KIDNEY: Case# 32994: HEMOPHELIA S/P ESWL WITH PERINEPHRIC HEMATOMA. Exam 1: 26 year old male with hemophilia. The patient is S/P lithotripsy approximately one week ago on the left for stones. Over a 12 hour period just prior to this examination the patient developed an enlarging palpable mass in the left mid abdomen. The patient is hemodynamically stable at the time of this examination. Exam 2: (2 days later) The patient is a 26 year old white male with hemophilia, S/P lithotripsy for left renal stones with subsequent retroperitoneal hemorrhage. This is a follow up examination. Exam 1:There is a large left retroperitoneal fluid collection which measures approximately 65 Hounsfield Units. There are small areas of high attenuation within this fluid collection. The left kidney is displaced anteriorly. Multiple foci of low attenuation seen within the left kidney. High attenuation fluid is noted within a mildly dilated collecting system on the left. There are small renal calculi also identified in the lower pole collecting system on the left. A small amount of hematoma is also identified in the left psoas muscle. There is a small amount of low attenuation perihepatic fluid. Exam 2: Comparison is made with the previous CT scan. The previously identified large retroperitoneal hematoma is again identified and has increased in size since the previous examination. In addition to a generalized approximately 2 cm increase in the overall dimensions, there is a new 6 x 8 cm area of hemorrhage posterior to the left kidney that was not seen on previous exam. As mentioned above the extension into the contralateral Gerotas fascia and anterior perirenal space as well as inferior extension has increased mildly. A residual amount of contrast material although smaller than previous scan is still present. The previously identified right groin muscle hematoma is not changed. No other interval changes are identified.