Presentation
One month history of neglected left flank pain.
Patient Data











Large well-defined left renal subcapsular mass, containing areas of fatty density with peripheral enhancement, perinephric fat stranding, and thickening with enhancement of the perirenal fascia.
Others findings:
small left renal stone
dilated CBD with no intraductal stone or soft tissue mass (history of cholecystectomy 30 years ago)
focal hepatic steatosis (segments 4 and 5)
vertebral osteoporosis with compression-fracture of L1 and L4 vertebral bodies.

Annotated image showing the mean attenuation of the fatty component and fluid content.
Case Discussion
CT features of a large renal mass of subcapsular location containing areas of fatty attenuation most consistent with spontaneous non-traumatic renal hemorrhage in a patient with renal angiomyolipoma (Wunderlich syndrome).
Wunderlich syndrome is a rare condition in which spontaneous non-traumatic renal hemorrhage occurs in the subcapsular and perirenal spaces. It may be due to neoplastic or non-neoplastic causes. Among benign neoplasms, angiomyolipoma is the commonest, while among malignancies, renal cell carcinoma is the commonest.
Additional contributor: Z.E Boudiaf, MD, CIM Aurès, Batna, Algeria