Figure 4

Intraoperative gross findings. Tumor resection was performed with the retroperitoneal approach from the right side by resecting the 11^th rib (A,B). The tumor existed in the swollen psoas muscle (*), adjacent to the posterior-distal edge of the pleural cavity (B, #). The tumor was an encapsulated, tan, elastic soft oval mass sized 11 × 8 × 8 cm (C). The cut surface was dark red with a central white zone of fibrosis and calcification (D).