A heterogenous rounded exophytic mass 4 cm in diameter arises from the upper pole of the left kidney. No contrast extravasation. Small foci of intralesional fat. The left renal artery and vein opacify normally. Dense retroperitoneal fluid with a density of 75 HU extending to the intraperitoneal cavity around the spleen and into the left paracolic gutter. Radiodense contrast from the prior scan within the bilateral renal calyces, proximal ureters, and bladder. The right kidney is normal.
The liver, gallbladder, pancreas, spleen, and adrenal glands are normal. No pneumoperitoneum. Normal caliber enhancement of the large and small bowel loops. Prominent, mesenteric lymph nodes, likely reactive.
The lung bases are clear. No suspicious osseous lesions.
Impression
Heterogenous left renal mass with retroperitoneal hemorrhage. The lesion contains macroscopic fat which makes an angiomyolipoma (AML) the most likely diagnosis. When this large, they have a propensity to bleed. Discussion with IR recommended regarding angioembolisation.