EXAM: , CT of abdomen with and without contrast.  CT-guided needle placement biopsy.,HISTORY: , Left renal mass.,TECHNIQUE: , Pre and postcontrast enhanced images were acquired through the kidneys.,FINDINGS: , Comparison made to the prior MRI.  There is re-demonstration of multiple bilateral cystic renal lesions.  Several of these demonstrate high attenuation in the precontrast phase of the exam suggesting that they are hemorrhagic cysts.  There was however one cyst seen in the lower pole of the left kidney, which demonstrated apparent enhancement from 30 to 70 Hounsfield units post contrast administration.  This measured approximately 1.4 x 1.3 cm to the exophytic half of the lower pole.  No other enhancing renal masses were seen.  The visualized liver, spleen, pancreas, and adrenal glands were unremarkable.  There are changes of cholecystectomy.  Mild prominence of the common bile duct is likely secondary to cholecystectomy.  There is no abdominal lymphadenopathy, masses, fluid collection, or ascites.,Lung bases are clear.  No acute bony pathology was noted.,IMPRESSION: , Solitary apparently enhancing left renal mass in the lower pole as described.  Renal cell carcinoma cannot be excluded.,CT-GUIDED NEEDLE BIOPSY, LEFT KIDNEY MASS: , Following discussion of risks, benefits, and alternatives, the patient wished to proceed with CT-guided biopsy of left renal lesion.  The patient was placed in the decubitus position.  The region overlying the left renal mass of note was marked.  Area was prepped and draped in usual sterile fashion.  Local anesthesia was achieved with approximately 8 mL of 1% lidocaine with bicarbonate.  The Versed and fentanyl were given to achieve conscious sedation.  Utilizing an 18 x 15 gauge coaxial system, 3 core biopsies were obtained through the mass in question, and sent to pathology for analysis.  Following procedure, scans through the region demonstrate a small subcutaneous hematoma in the region of the superficial anesthesia.  No perinephric fluid/hematoma was identified.  The patient tolerated the procedure without immediate complications.,IMPRESSION: , Three core biopsies through the region of the left renal tumor as described.surgery, ct, ct-guided, ct-guided biopsy, hounsfield units, mri, abdomen, biopsy, cholecystectomy, contrast, contrast administration, decubitus position, images, needle, postcontrast, renal lesions, renal mass, renal tumor, with and without, ct guided needle placement, ct of abdomen, needle placement, lower pole, ct guided, renal