Figure 1.

Computed tomography findings of three retroperitoneal ancient schwannomas. A. Large partly cystic and solid tumor displacing the pancreas and splenic vein anteriorly and compressing left kidney. Tumor concerning for a sarcoma or pancreatic neoplasm. B. Well defined tumor extending from the retroperitoneum into left pelvis adjacent to sigmoid colon. Region of vascular enhancement around tumor periphery can clearly be seen. C&D. Large heterogeneous enhancing mass adjacent to the aorta and left kidney shown in transverse and sagittal sections. Partial encasement of the aorta and left renal artery is demonstrated concerning for a malignancy.