Asymmetric crypt fission in colectomy specimens in patients with ulcerative colitis

Abstract

AimsWe previously found colonic crypts with asymmetric fission bordering regenerating ulcers in ulcerative colitis (UC). The present objective was to assess the frequency of asymmetric crypt-fission in colectomy specimens from patients with long-lasting UC.MethodsH&E-stained sections from seven colectomies from patients with UC without dysplasia or carcinoma were investigated. Symmetric fission was characterised by branched colon crypts showing ≥2 identical crypts, whereas asymmetric fission exhibited branched colon crypt portraying ≥2 dissimilar crypts, differing in diameter, length and/or shape.ResultsThe number of crypts in fission in the 89 sections was 3586; of those, 2930 (81.7%) were asymmetric and the remaining 656 (18.3%), symmetric. Out of 927 vertically-cut crypts (in well-oriented sections), 912 (98.4%) were asymmetric, and the remaining 14 (1.6%), symmetric, and out 2660, cross-cut (transected) crypts in fission, 2018 (75.9%) were asymmetric and the remaining 642 (24.1%), symmetric.ConclusionCrypt fission is rarely found in the normal colon in adults. Symmetric crypt fission found in UC is possibly triggered by a compensatory homeostatic mechanism of crypt production in mucosal areas replaced by chronic inflammation. But asymmetric crypt fission is a pathological aberration that affects crypts in patients with a particular predisposition to develop mucosal dysplasia. It is suggested that this previously unattended histological parameter be included in the pathological descriptions of colectomy specimens from patients with UC.

Crypts in Asymmetric Fission in Endoscopic Biopsies from Swedish Patients With Inflammatory Bowel Disease

“…Subsequently, while studying sections cut in a vertical plane, we found at the edge of mucosal ulcers in three colectomy specimens with UC, 70 crypts with architectural distortions; 30 (43%) of those were in asymmetric fission (16). In a more recent study of seven colectomy-specimens from patients with UC, having sections cut in a vertical plane, albeit with random cross-cut-crypts areas, we found crypts with architectural distortions, including 3,586 crypts in fission; of those, 2,930 (82%) were in asymmetric fission (17). From these findings, it was deduced that crypts in asymmetric fission often occur in specimens from colectomy specimens with UC.…”

Branching crypts in inflammatory bowel disease revisited

“…Apparently, the presence of neoplastic tissue elsewhere in the specimen did not increase the frequency of crypt fission in colectomies with UC. In a third survey comprising seven colectomy‐specimens with UC without dysplasia or carcinoma, 3587 crypts in fission were found: 82% of those were in asymmetric fission 17 . Notably, out of 927 upright crypts, 98% were in asymmetric fission, and the remaining 2%, in symmetric fission.…”

“…Notably, out of 927 upright crypts, 98% were in asymmetric fission, and the remaining 2%, in symmetric fission. On the other hand, out of 2660 cross‐cut crypts in fission recorded, 76% were in asymmetric fission and the remaining 24%, in symmetric fission 17 …”

Crypts in Asymmetric Fission in Endoscopic Biopsies from German Patients With Inflammatory Bowel Disease

“…In inflammatory bowel disease (IBD) [including ulcerative colitis (UC) and Crohn's colitis (CCs)], large mucosal areas are replaced by chronic inflammation (10,11). In these large mucosal areas, a regenerative process relentlessly ensues, including the boosting of crypt fission (6).…”

“…Despite crypt branching being mentioned in most histologic reports in patients with IBD, only but few isolated histologic studies have described the various phenotypes of crypt branching in sections from colectomy specimens (6) or from endoscopic biopsies in IBD patients (8). In well-oriented, upright crypts in IBD, the point of crypt-branching (the starting "point" of crypt fission) may be found at any level along the height of the crypt, from the top to the bottom, but in IBD biopsies, the point of crypt fission is identified by back-to-back crypts being apart by an epithelial septum (9).…”