FIGURE 1.

Imaging studies of the chest with the relevant timeline. (a–c) Chest contrast‐enhanced computed tomography (CT) scan revealed a tumor lesion that was fused between the left hilum and mediastinum (white arrow). The tumor enveloped the left pulmonary artery, and nodules were detected in both lung fields (black arrow). (d) A chest contrast‐enhanced CT scan taken eight months after the initiation of treatment showed a reduction in the tumor size around the left pulmonary artery. (e: cross‐section, f: coronal‐section) A pelvic contrast‐enhanced CT scan taken at the same time as that of (d) revealed soft tissue shadows around the abdominal aorta that had increased in size (arrowheads). Soft tissue shadows around the bladder and seminal vesicles had also increased in size. (g: cross‐section, h: coronal‐section) A positron‐emission tomography (PET‐CT) scan taken at the same time as that of (d) showed accumulation around the abdominal aorta and bladder. (i: cross‐section, j: coronal‐section) One month after the initiation of steroid treatment, a CT scan showed a reduction in the soft tissue shadow around the abdominal aorta.