Difficulty in differentiating two cases of sigmoid stenosis by diverticulitis from cancer

The incidence of colonic diverticulosis with or without diverticulitis has increased in the Japanese population due to the modernization of food and aging. The rate of diverticulitis in colon diverticulosis ranges from 8.1% to 9.6%. However, few cases of stenosis due to diverticulitis have been reported. These reports suggest that the differentiation between sigmoid diverticulitis and colon cancer is difficult. This report describes two cases of colon stenosis due to diverticulitis that were difficult to differentiate from colon cancer. Case i was a 70-year-old woman with narrowed stools for 1 month who underwent colonofiberscopy （CFS）. CFS revealed a diverticulum and circumferential stenosis in the sigmoid colon. Barium enema revealed a marked, hourglass- shaped, 2-cm circumferential stenosis in the sigmoid colon. Fluorodeoxyglucose （FDG）-positron emission tomography computed tomography （CT） revealed an increased FDG uptake at the affected portion of the sigmoid colon. Sigmoid colon cancer was suspected,and laparoscopic sigmoidectomy was performed. Patho- logical examination demonstrated active inflammation with no evidence of malignancy. Case 2 was a 50-year- old man who presented to a nearby clinic with reduced stool output despite the urge to defecate. CFS detected severe stenosis in the sigmoid colon approximately 25 cm from the dentate line. Contrast-enhanced abdomi- nal CT revealed multiple diverticula, wall thickening, and swelling of the lymph nodes around the peritoneal aorta and the inferior mesenteric artery. A partial sig- moidectomy was performed. Pathological examination of the resected specimen revealed no changes in the mucosal epithelial surface, but a marked infiltration of inflammatory cells was observed.

In vivo detection of mucosal healing-involved histiocytes by confocal laser endomicroscopy

Histiocytes have a pivotal role in wound repair and intestinal epithelial recovery-the most important goal to sustain gut functionality.Yet,an in vivo description of colonic histiocytes by confocal laser endomicroscopy(CLE) is missing.Here,we report the case of a 45-yearsold male patient who was referred to our clinic with weight loss and a history of two consecutive Clostridium difficile colitis episodes,the latter cured 3 wk before present admission.Stool microbiology was negative.Conventional colonoscopy showed atrophy and a light mucosal oedema in the distal colon.During on-going endoscopy,we performed a fluorescein-aided CLE which revealed large polygonal(histiocytes-like) cells with copious cytoplasm and large nuclei in the lamina propria of the sigmoid colon as well as regenerative epithelial changes.Histopathological assessment of biopsies from the same areas confirmed the endomicroscopical findings:Periodic acid-Schiff-and CD68-positive foamy histiocytes in the colonic lamina propria and an advanced epithelial recovery.Since stool microbiology was repeatedly negative and polymerase chain reaction-analysis from colonic biopsies could not detect any mRNA for Thropheryma whippleii and common pathogens,we interpreted this particular setting as a mucosal healing process after consecutive Clostridium difficile infections.In conclusion,by describing these colonic histiocytes,we highlight the clinical usefulness of CLE in describing the entity of histiocytes in vivo and in real-time during the process of post-infectious mucosal healing in the colon.