Fig. 1. Findings of imaging studies of IgG4-related disease of rectum. (A, B) Colonoscopic view of low rectum: 2-cm-sized protruding mass; (C) colonoscopic endoluminal ultrasonography view: 2-cm-sized heterogeneous low echogenic lesion involving mucosal, submucosal and proper muscle layer; (D) T1-weighted MRI. A 1.4-cm T1 low signal intensity mass (arrow) involving or abutting right anterior wall of lower rectum.
