Mature teratoma in a 23-year-old female. CT scan showing a retroperitoneal mass with fat components, cystic areas, and calcifications (arrow). These findings, especially the fat component, are suggestive of a germ-cell origin. Note the anterior displacement of the aorta in relation to the vertebral body-an indirect sign of retroperitoneal location (arrowhead). The diagnosis was confirmed by percutaneous biopsy.