Presentation
Metastatic workup for right breast cancer.
Patient Data
Rather well circumscribed rounded shaped soft tissue mass is seen at the left pre-renal retroperitoneal space showing heterogeneous CT architecture of dominant fat density (-45 HU), soft tissue strands and tumoral vessels seen traversing to the renal parenchyma. It is seen abutting the anterior aspect of the right kidney with an anterior renal parenchyma cortical defect is seen continuous with the mass. No internal discrete enhancing nodules were seen. It measures 6.8 x 7.8 x 8.3 cm in maximal axial and craniocaudal dimensions. The feeder artery of the mass is seen originating from the left renal artery.
Other much smaller three fat density nodules are seen within the right renal cortex, the largest measuring 9 mm in diameter and reading a mean attenuation -40 HU. No renal back pressure changes.
Case Discussion
Left retroperitoneal pre-renal fat containing soft tissue mass with a renal parenchymal defect, other smaller right renal parenchymal fat containing nodules (angiomyolipomas), vascular supply from the renal artery as well as a lack of discrete internal enhancing nodules are in keeping with an exophytic renal angiomyolipoma.