PMC4189076_01
(A, B) Colonoscopy revealed moderate stenosis caused by edematous wall thickening of the lower ascending colon with reddening of the mucosa (A) and a swollen ileocecal valve (B; arrow). (C) A radiographic contrast enema indicated the presence of edematous asymmetrical stenosis, with erosion of the terminal ileum and lower ascending colon (arrow, ascending colon; dotted arrow, terminal ileum). (D, E) Abdominal CT scans indicated edematous wall thickening of the lower ascending colon (D; arrow) and terminal ileum (E; arrow). (F) FDG-PET revealed increased FDG uptake in the ascending colon (SUV max: 13.3; black dotted arrow), terminal ileum (SUV max: 6.9; white dotted arrow), spleen (SUV max: 5.9; black arrow) and paraaortic lymph node (SUV max: 5.3; white arrow).
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Colonoscopy revealed moderate stenosis caused by edematous wall thickening of the lower ascending colon, with reddening of the mucosa (Fig. 1A). Since the ileocecal valve was also swollen, the scope could not be inserted into the terminal ileum (Fig. 1B). A radiographic contrast enema indicated edematous asymmetric stenosis with erosion from the terminal ileum to lower ascending colon (Fig. 1C). An abdominal computed tomography (CT) scan indicated edematous wall thickening from the terminal ileum to the lower ascending colon (Fig. 1D and E). Positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) revealed increased FDG uptake in the ascending colon (SUV max: 13.3), terminal ileum (SUV max: 6.9), and also in the spleen (SUV max: 5.9) and paraaortic lymph node (SUV max: 5.3) (Fig. 1F).
(A) The segmental bowel resection included 25 cm of ascending colon and 125 cm of ileum. There was an irregular wall thickness with submucosal sclerosis, which was 10 cm in length from the terminal ileum to the ascending colon, accompanied by sclerosis of the mesentery of the ileum (arrow). (B, C) Hematoxylin-eosin staining showed lymphoplasmacytic infiltration, lymphoid follicles and fibrosis in the subserosa and surrounding adipose tissue (arrow). (D) Elastica van Gieson (EVG) staining showed obliterative phlebitis (arrow). (E) Immunohistochemical staining revealed an increased number of IgG4-positive plasma cells at 150/HPF (400x), and an increased IgG4/IgG ratio (50%).
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Grossly, the segmental bowel resection included 25 cm of ascending colon and 125 cm of ileum (Fig. 2A). Microscopically, the lesion was composed of the ileal, cecal and colonic wall with lymphoplasmacytic infiltration, lymphoid follicles and fibrosis in the subserosa and surrounding mesenteric adipose tissue (Fig. 2B and C). IgG4-RD (Fig. 2D). Immunohistochemical staining revealed an increased number of IgG4-positive plasma cells at 150/HPF (400x), and the IgG4/IgG ratio was 50% (Fig. 2E).