Imaging features of retroperitoneal and pelvic schwannomas

Retroperitoneal and pelvic schwannomas typically form large, well-circumscribed masses in the retroperitoneum or presacral area, and frequently undergo cystic degeneration. They can occasionally cause bony changes in the spine, but otherwise do not invade or obstruct adjacent structures. Although they are rare, it is important for the radiologist to recognize the typical appearance of schwannomas because they can be mistaken for malignant tumours.