case_images: PMC5465708_01
case_images: PMC5465708_02
case_images: Colonoscopy findings before treatment: observation up to the transverse colon. Extensive undermining ulcers, severe mucosal edema, and scope contact-induced hemorrhage were observed in the transverse colon (a) over the sigmoid colon. Although mucosal edema was present in the rectum (b), only partially visible vascular patterns and erosion were observed. Results of rectal biopsy (c): mucosa with relatively marked inflammatory cell infiltration including neutrophils and regenerative changes. No epithelioid granuloma or active vasculitis was observed. The histopathological diagnosis was ulcerative colitis with mild activity, compatible ulcerative colitis. Diffuse inflammatory cell infiltration (++), reduction of germinal (goblet suspicion) cells (+), regressive change of glandular epithelium (+-), crypt abscess (-), disturbed gland duct arrangement (+), gland regeneration (+), Paneth cells (-).
case_images: crg-0011-0168-g01.jpg
case_images: PMC5465708_02_crg-0011-0168-g01.jpg
case_images: f1
case_images: Extensive ulceration or undermining ulcer, reduction of visible vascular patterns, and hemorrhagic tendency were noted in the transverse colon compared to the rectum (Fig. 1). Mucosal edema was noted in the rectum, but visible vascular patterns and erosion were only partially observed (Fig. 1).
case_images: Colonoscopy findings at week 2 of tacrolimus administration. The scope was inserted up to the end of the ileum. No reddening or erosion was noted at the end of ileum. Bauhin's valve was slightly dilated. In the ileocecum (a) over the ascending colon, mild mucosal edema was observed. In the transverse colon (b) over the sigmoid colon, edema was moderate and extensive ulcers were observed, but the mucosa of the ulcer floor was regenerated and flattened. Only partial reddening was noted (c).
case_images: crg-0011-0168-g02.jpg
case_images: PMC5465708_02_crg-0011-0168-g02.jpg
case_images: f2
case_images: In the rectum, only partial congestion was noted (Fig. 2).
case_images: Colonoscopy findings at week 4 of tacrolimus administration. The scope was inserted up to the cecum. Bauhin's valve was slightly dilated. In the ileocecum (a) over the ascending colon, mild mucosal edema was observed. In the transverse colon (b) over the sigmoid colon, edema was moderate, the mucosa of the floor of the extensive ulcers was further regenerated and flattened, and reddening inflammatory polyps were noted. Rectal erosion had resolved as observed on the previous colonoscopies (c).
case_images: crg-0011-0168-g03.jpg
case_images: PMC5465708_02_crg-0011-0168-g03.jpg
case_images: f3
case_images: Another colonoscopy performed at the end of the 4-week tacrolimus treatment showed slight congestion of Bauhin's valve, mild mucosal edema from the ileocecum to the ascending colon, mild edema in the transverse colon to the sigmoid colon, with further regeneration and flattening of ulcer floor mucosa compared with that on the previous colonoscopy, persistent disappearance of rectal erosion as observed on previous colonoscopy, together with congested inflammatory polyps (Fig. 3).
case_images: Colonoscopy findings at week 6 of tacrolimus administration. The scope was inserted up to the end of the ileum. No reddening or erosion was observed at the end of the ileum (a). Bauhin's valve (b) was slightly dilated, and a round ulcer was formed in the inferior lip of Bauhin's valve. In the ileocecum over the ascending colon, visible vascular patterns were reduced. In the transverse colon (c) over the sigmoid colon, ulcer scars and inflammatory polyps were noted. Visible vascular patterns were partially improved. Rectal erosion had resolved as observed on the previous colonoscopies. Results of biopsy from the margin of the ulcer in Bauhin's valve (d): the mucosa showed mild activity. Gland tissue showed extension and slight dentate changes, but the nuclei were small. Diffuse inflammatory cell infiltration (+), decrease in germinal (goblet suspicion) cells (+-), regressive change of glandular epithelium (-), crypt abscess (-), disturbed gland duct arrangement (+), gland regeneration (+), Paneth cells (-).
case_images: crg-0011-0168-g04.jpg
case_images: PMC5465708_02_crg-0011-0168-g04.jpg
case_images: f4
case_images: Colonoscopy performed at the end of week 6 of tacrolimus treatment showed no congestion or erosion at the end of the ileum, slight dilation of Bauhin's valve, a new round ulcer in the inferior lip of Bauhin's valve, fewer areas with visible vascular patterns in the ileocecum to the ascending colon, ulcer scars and inflammatory polyps in the transverse colon to the sigmoid colon, partial improvement of the visible vascular patterns, and lack of erosion in the rectum (Fig. 4).
case_images: PMC5465708_03
case_images: Colonoscopy findings at week 12 of tacrolimus administration. The scope was inserted up to the end of the ileum. Erosion was present at the end of the ileum (c). Bauhin's valve (a, b) was slightly dilated, and the round ulcer expanded compared with that on the previous colonoscopies. In the ileocecum over the ascending colon, reddening was partially noted, but visible vascular patterns were improved. In the transverse colon (b) over the sigmoid colon, ulcer scars and inflammatory polyps were noted but shrunk compared with those on the previous colonoscopies. Healed mucosa was noted in the rectum.
case_images: crg-0011-0168-g05.jpg
case_images: PMC5465708_03_crg-0011-0168-g05.jpg
case_images: f5
case_images: Colonoscopy performed at 12 weeks after the start of tacrolimus treatment showed erosion at the end of the ileum, slight dilation of Bauhin's valve, extension of the round ulcer compared with previous colonoscopy, partial congestion of the ileocecum to the ascending colon, improvement of visible vascular patterns, shrinking ulcer scars and inflammatory polyps in the transverse colon to the sigmoid colon, and complete healing of the rectal mucosa (Fig. 5). Colonoscopy at the end of 18 weeks of tacrolimus treatment showed only small erosion and slight congestion in the ileocecum, and few areas of mucosal congestion and small erosions scattered in other regions of the large intestine (Fig. 5).
case_images: Colonoscopy findings at week 18 of tacrolimus administration. The scope was inserted up to the end of the ileum. Reddening and erosion were absent at the end of the ileum (c). Bauhin's valve (a, b) was slightly dilated, and small erosion was noted. Biopsy 1: mucosal atrophy was noted in the ileocecum over the ascending colon. In the transverse colon (b) over the sigmoid colon, ulcer scars, inflammatory polyps, and partial mucosal healing were observed. Healed mucosa was noted in the rectum. Results of biopsy of erosion collected from Bauhin's valve (d): mucosa with very mild activity. Diffuse inflammatory cell infiltration (+), decrease in germinal (goblet suspicion) cells (+-), regressive change of glandular epithelium (-), crypt abscess (-), disturbed gland duct arrangement (+), gland regeneration (+), Paneth cells (-).
case_images: crg-0011-0168-g06.jpg
case_images: PMC5465708_03_crg-0011-0168-g06.jpg
case_images: f6
case_images: A repeat colonoscopy at 36 weeks of tacrolimus treatment showed only slight congestion in the ileocecum and healing of the mucosa in other regions (Fig. 6).