Diversion colitis in children: an iatrogenic appendix vermiformis?

AIMS: Diversion colitis (DC) is a localized, relatively benign, iatrogenic condition which occurs in almost 100% of diverted colonic segments in patients who undergo ileostomy/colostomy for various reasons. The aim of this study was to establish histological features of DC in children. METHODS AND RESULTS: Twenty-three cases of DC following colostomy for Hirschsprung's disease in young children were analysed. The distinguishing features included prominent follicular lymphoid hyperplasia (100%), chronic mucosal inflammation (100%), accompanied by a variable degree of acute inflammation (78%) and Paneth cell metaplasia (26%). Less frequent histological findings were as follows: mild goblet cell depletion (22%), foci of cryptitis (13%), crypt abscesses (13%) and mild architectural distortion (22%). A previously unrecognized feature was the presence of mucosal aggregates of eosinophils, found in 43% of cases. A striking similarity between the normal appearance of the vermiform appendix and pathological features in DC was noted and the possible relationship between the two is discussed. CONCLUSIONS: Histological features of DC in children are very similar to those described in adults. They should help to distinguish it from ulcerative colitis and Hirschsprung's-associated enterocolitis in order to prevent inappropriate therapy and follow-up. There are many similarities between DC and the normal appendix vermiformis.     

Late-Onset Colitis after Cord Blood Transplantation Is Consistent with Graft-Versus-Host Disease: Results of a Blinded Histopathological Review

Cord colitis syndrome after umbilical cord blood transplantation (UCBT) involves late-onset diarrhea, absence of infection or GVHD, chronic active colitis, and granulomatous inflammation that responds to antibiotics. We tested the hypothesis that Seattle recipients of UCBT had late-occurring colitis distinct from GVHD and colitis in other allograft recipients. We conducted a blinded histological review of 153 colon biopsy specimens from 45 UCBT recipients and 45 matched allografted controls obtained between day +70 and day +365 post-transplantation. Diarrhea was the primary indication for biopsy in 10 UCBT recipients and 11 controls. No histological differences were seen between UCBT recipients and controls with diarrhea or between the entire cohort of UCBT recipients and their controls. Distorted mucosal architecture and apoptotic crypt cells typical of GVHD were common in both groups; Paneth cell metaplasia and granulomas were rare findings. Chronic active colitis was present in 58% of the UCBT recipients and in 62% of controls. No UCBT recipient with diarrhea was treated with antibiotics, and all recipients responded to systemic corticosteroids. Colitis occurring after day +70 in allografted controls was related to acute GVHD, independent of the source of donor cells. We could not identify a histologically distinct cord colitis syndrome in either the UCBT or the non–cord blood allograft recipients.     

Histological discrimination of idiopathic inflammatory bowel disease from other types of colitis.

AIMS--To assess the value of histology in diagnosing inflammatory bowel disease (IBD) in colorectal biopsy specimens. METHODS--Retrospective, double blind evaluation of colorectal biopsy specimens from 41 patients with colitis (28 with ischaemic colitis and 13 with acute self-limited colitis) and 84 patients with IBD (42 with Crohn''s disease and 42 with ulcerative colitis). RESULTS--The features distinguishing IBD from other forms of colitis included distorted architecture, lymphocyte and plasma cell infiltrate, excess of polymorphonuclear leucocytes, polymorphonuclear cryptitis, crypt abscesses, and basal lymphoid aggregates. The features discriminating between Crohn''s disease and ulcerative colitis included an irregular or villous surface, distorted architecture, decrease in mucus content, and polymorphonuclear cryptitis. Using multivariate analysis, 90% of patients with Crohn''s disease and 71% of those with ulcerative colitis were correctly classified, the former being strongly defined by epithelioid granulomas, microgranulomas and isolated giant cells, and the latter best defined by an irregular or villous surface, decrease in mucus content and crypt atrophy. CONCLUSIONS--Examination of colorectal biopsy specimens is a reliable method for diagnosing IBD. In the absence of epithelioid granulomas, microgranulomas and isolated giant cells a diagnosis of Crohn''s disease is based on the absence of histological criteria favouring ulcerative colitis. The histological spectrum of indeterminate colitis remains to be clarified.     

Granulomatous ulcerative colitis: a re-appraisal of the mucosal granuloma in the distinction of Crohn's disease from ulcerative colitis

AIMS: To determine whether the presence and location of giant cells or granulomas in relation to crypts distinguishes between ulcerative colitis and Crohn's disease. METHODS AND RESULTS: Twenty-nine large bowel mucosal biopsy specimens showing giant cells and/or granulomas in a background more typical of ulcerative colitis than Crohn's disease were collected between 1986 and 1996. Each was subject to detailed independent analysis by three histopathologists. Follow-up of the cases was by examination of all previous and subsequent gastrointestinal surgical or biopsy material and by scrutiny of the clinical notes by a gastroenterologist. On the basis of the accumulated histological data 10 of these 29 cases were accorded the diagnosis of ulcerative colitis. In nine of these 10 cases the clinical diagnosis, where known, was in keeping with this and all nine contained only crypt-associated giant cells and/or granulomas. The tenth case contained a solitary free-standing granuloma and clinically the patient had perianal disease, suggesting that the true diagnosis was Crohn's disease. CONCLUSIONS: Isolated giant cells and well-defined epithelioid granulomas distant from crypts do not, as a rule, occur in ulcerative colitis, and hence their presence in a colonoscopic biopsy showing features of chronic inflammatory bowel disease is a strong pointer towards the diagnosis of Crohn's disease. Crypt-associated giant cells and granulomas can occur in ulcerative colitis and in themselves are unreliable features for the discrimination between Crohn's disease and ulcerative colitis.     

Vascular Microarchitecture of Murine Colitis‐Associated Lymphoid Angiogenesis

In permissive tissues, such as the gut and synovium, chronic inflammation can result in the ectopic development of anatomic structures that resemble lymph nodes. These inflammation‐induced structures, termed lymphoid neogenesis or tertiary lymphoid organs, may reflect differential stromal responsiveness to the process of lymphoid neogenesis. To investigate the structural reorganization of the microcirculation involved in colonic lymphoid neogenesis, we studied a murine model of dextran sodium sulfate (DSS)‐induced colitis. Standard 2‐dimensional histology demonstrated both submucosal and intramucosal lymphoid structures in DSS‐induced colitis. A spatial frequency analysis of serial histologic sections suggested that most intramucosal lymphoid aggregates developed de novo. Intravital microscopy of intravascular tracers confirmed that the developing intramucosal aggregates were supplied by capillaries arising from the quasi‐polygonal mucosal plexus. Confocal optical sections and whole mount morphometry demonstrated capillary networks (185 ± 46 μm diameter) involving six to ten capillaries with a luminal diameter of 6.8 ± 1.1 μm. Microdissection and angiogenesis PCR array analysis demonstrated enhanced expression of multiple angiogenic genes including CCL2, CXCL2, CXCL5, Il‐1b, MMP9, and TNF within the mucosal plexus. Intravital microscopy of tracer particle flow velocities demonstrated a marked decrease in flow velocity from 808 ± 901 μm/sec within the feeding mucosal plexus to 491 ± 155 μm/sec within the capillary structures. We conclude that the development of ectopic lymphoid tissue requires significant structural remodeling of the stromal microcirculation. A feature of permissive tissues may be the capacity for lymphoid angiogenesis. Anat Rec, 292:621–632, 2009. © 2009 Wiley‐Liss, Inc.     

The rectal biopsy appearances in Salmonella colitis

Rectal biopsies were examined from 22 patients with Salmonella infection of food-poisoning type and from seven patients with inflammatory bowel disease and coincidental Salmonella infection. In the former group the changes observed were mucosal oedema with acute inflammation of varying severity but with preservation of the crypt architecture. Crypt abscesses were present in a few cases but were usually localized in the crypt and mucus depletion only occurred with severe inflammation. These features are not specific and are similar to those seen in other types of infective colitis such as Shigella dysentery, gonococcal proctitis and amoebic colitis. In the majority of cases of infective colitis the appearances are usually sufficiently distinctive, however, to distinguish them from those seen in ulcerative colitis and Crohn's disease. The changes in the biopsies from the seven patients with coincidental Salmonella infection were in general those of the underlying idiopathic inflammatory bowel disease.     

Indeterminate colitis: definition, diagnosis, implications and a plea for nosological sanity

In 1978, Price introduced the concept of indeterminate colitis to describe cases in which colonic resections had been undertaken for chronic inflammatory bowel disease (CIBD), but a definitive diagnosis of either of the classical types of CIBD, ulcerative colitis and Crohn's disease, was not possible. This was especially apposite in cases of acute fulminant disease of the colorectum. More recently, the term indeterminate colitis has been applied to biopsy material, when it has not been possible to differentiate between ulcerative colitis and Crohn's disease. In our opinion, and in those of other workers in this field, the term should be restricted to that originally suggested by Price. This then provides a relatively well-defined group of patients in whom the implications and management of the disease are becoming much clearer. Cases where there are only biopsies with CIBD, but equivocal features for ulcerative colitis and Crohn's disease, should be termed 'CIBD, unclassified', 'equivocal/non-specific CIBD' or IBD unclassified (IBDU), in line with recent recommendations. When the diagnosis is correctly restricted to colectomy specimens, there is now good evidence that the majority of cases will behave like ulcerative colitis. Furthermore, the diagnosis should not be a contraindication to subsequent pouch surgery. When the latter is undertaken, surgeons and patients can expect an increased complication rate, compared with classical ulcerative colitis, especially of pelvic sepsis, but most patients fare well. Only very occasional patients, around 10%, will eventually be shown to have Crohn's disease. This review describes the pathology of cases appropriately classified as indeterminate colitis and the implications of that diagnosis. It also highlights recent advances in its pathological features, clinical management and its immunological and genetic associations.     

Intramucosal ganglion cells are common in diverticular disease

AIMS: Ganglion cells were thought not to occur within the mucosa of the normal colon and found only in the setting of inflammatory bowel disease and neuronal intestinal dysplasia. The aim of this study was to firmly establish the incidence of intramucosal ganglion cells in diverticular disease, normal mucosa and in a spectrum of gastrointestinal diseases. METHODS: We retrospectively reviewed 50 resection specimens from cases of symptomatic diverticular disease and biopsies and/or resection specimens for several neoplastic and non-neoplastic gastrointestinal diseases (50 normal and 120 cases for a variety of gastrointestinal diseases). Normal cases were constituted by biopsies with no clinical history of large bowel disease and no pathology detected microscopically. RESULTS: All 50 cases of diverticular disease contained intramucosal ganglion cells, located within the muscularis mucosae (49/50 cases) as well as within the lamina propria in nine cases. Intramucosal ganglion cells occurred throughout the colorectum within the muscularis mucosae or lamina propria in normal mucosa in 11 cases and in a further 26 colorectal specimens with Crohn's disease (11/20), ulcerative colitis (11/20), adenocarcinoma (1/20), tubular adenoma (2/20), and mucosal prolapse (1/20). None of the 20 hyperplastic polyps contained intramucosal ganglion cells. CONCLUSIONS: We have firmly established the existence of the intramucosal ganglion cells in normal and diseased colorectum, especially in the mucosa of cases of diverticular disease (100% of cases), Crohn's disease and ulcerative colitis. These three conditions are linked by motility abnormalities which may underlie the reason for the presence of intramucosal ganglion cells.     

Enteroendocrine cell hyperplasia, carcinoid tumours and adenocarcinoma in long-standing ulcerative colitis

Chronic ulcerative colitis may be accompanied by a variety of epithelial changes, including loss of goblet cells, Paneth cell metaplasia, villous metaplasia, and dysplasia. Total colitis is also accompanied by an increased incidence of adenocarcinoma. All these changes are assumed to be secondary to repeated mucosal damage, but how they develop is unknown. Little attention has been paid to the enteroendocrine cell population, despite the postulated role of these cells as producers of trophic hormones. We describe two patients with long-standing ulcerative colitis who developed both adenocarcinoma and carcinoid tumours. In both, there were increased numbers of enteroendocrine cells in the uninvolved colonic mucosa. We suggest that an increased enteroendocrine cell mass may be part of a non-specific reaction to chronic mucosal injury, and by producing an elevated level of trophic hormones may act as a promoter in the development of neoplasia.     

Microscopic colitis with granulomatous inflammation

AIMS: To present four cases in which the clinical and endoscopic findings were consistent with microscopic colitis, but the inflammatory infiltrate included a conspicuous granulomatous reaction. Microscopic colitis is defined as a syndrome of chronic watery diarrhoea with a chronic inflammatory cell infiltrate in the colonic mucosa and without significant abnormalities at colonoscopy. It encompasses both collagenous and lymphocytic colitis. METHODS AND RESULTS: In all cases the clinical course and endoscopic findings were unlike Crohn's disease and no infectious agents were identified. In all cases the main symptom was frequent watery diarrhoea, all were female and there were no endoscopic findings apart from mild mucosal erythema. Histologically, an active chronic inflammatory infiltrate was accompanied by scattered non-necrotizing granulomas, often closely associated with crypt epithelium (cryptolytic or pericryptal granulomas). In three of the patients the symptoms began after antibiotic use or had worsened with antibiotic use. Two of the patients were on allopurinol at the time of the onset of symptoms. In two of the patients symptoms have continued for more than 10 years. One patient died as a result of medical complications relating to severe diarrhoea and dehydration. CONCLUSIONS: Microscopic colitis rarely may be characterized by granulomatous inflammation. Such patients should not be regarded as having Crohn's disease.     

Immunohistochemical assessment of Ki67 and p53 expression assists the diagnosis and grading of ulcerative colitis-related dysplasia

AIMS: To assess whether Ki67 and p53 immunostaining may assist the diagnosis and grading of ulcerative colitis-related dysplasia. METHODS AND RESULTS : Location of Ki67 staining and location and intensity of p53 staining were assessed in ulcerative colitis (UC) cases showing the features of high-grade dysplasia (HGD, n = 14), low-grade dysplasia (LGD, n = 22), 'indefinite for dysplasia' (n = 12), or regenerative atypia (RA, n = 22). Good intra- and inter-observer reproducibilities were demonstrated in the performance of these assessments. All the dysplasia cases showed extension of Ki67 staining above the basal third of the crypt. Moderate intensity p53 staining was seen in 10/22 RA cases, but strong intensity p53 staining was seen only in cases of dysplasia. All the cases of HGD showed extension of Ki67 and p53 staining above the basal two thirds of the crypt. CONCLUSIONS: Restriction of Ki67 staining to the basal third of the crypt appears to exclude a diagnosis of dysplasia whereas strong intensity p53 staining suggests a diagnosis of dysplasia. Restriction of Ki67 or p53 staining to the basal two-thirds of the crypt appears to exclude a diagnosis of HGD.     

Simple objective criteria for diagnosis of causes of acute diarrhoea on rectal biopsy.

AIM: To identify simple, objective, accurate histological criteria for distinguishing acute infective-type colitis, chronic idiopathic inflammatory bowel disease, and irritable bowel syndrome on rectal biopsy in patients with acute onset diarrhoea at first presentation, one to 10 weeks after onset. METHODS: Cell counts and measurements of mucosal architecture were made on initial rectal biopsies from 18 patients with acute infective-type colitis, 17 patients with first acute presentation of chronic idiopathic inflammatory bowel disease, and 23 patients with irritable bowel syndrome. The data were analysed by ANOVA and discriminant analysis. RESULTS: Lamina propria cells were mainly in the upper third in irritable bowel syndrome patients. Increased lamina propria cellularity, mainly in the middle third, and numbers of crypt intraepithelial neutrophils distinguished acute infective-type colitis from irritable bowel syndrome in 93% of cases. Chronic idiopathic inflammatory bowel disease differed from irritable bowel syndrome and acute infective-type colitis in a decreased number of crypts and altered crypt architecture. Chronic idiopathic inflammatory bowel disease showed higher lamina propria cellularity, especially in the basal third, with an increased number of lamina propria neutrophils. On discriminant analysis, crypt numbers distinguished 86% of the cases of chronic idiopathic inflammatory bowel disease from the other groups. CONCLUSION: At one week or more from onset, acute infective-type colitis is characterised by a superficial increase in lamina propria cellularity, with only a slight increase in the number of polymorphs. At this stage, chronic idiopathic inflammatory bowel disease is characterised by a transmucosal increase in cellularity together with crypt loss and architectural abnormality. Thus, measurement of mucosal architecture establishes simple, accurate, objective criteria for routine biopsy diagnosis of chronic idiopathic inflammatory bowel disease from acute infective-type colitis and irritable bowel syndrome at initial presentation, one to 10 weeks after onset.     

Diagnostic difficulties in inflammatory bowel disease pathology

This review summarizes some of the common diagnostic problems encountered by pathologists when evaluating patients with chronic colitis and in whom inflammatory bowel disease (IBD) is either suspected or within the differential diagnosis. Both ulcerative colitis (UC) and Crohn's disease (CD) show characteristic, but non-specific, pathological features that may overlap and result in a diagnosis of 'indeterminate colitis' (IC). However, other reasons why pathologists may entertain a diagnosis of IC include failure to recognize or accept certain 'hardcore' histological features as indicative of CD, an attempt to classify cases of chronic colitis based on mucosal biopsy material or in the absence of adequate clinical and radiographic information, and the presence of other disease processes that mask, or mimic, IBD. In addition, some cases of UC may show unusual CD-like features, such as discontinuous or patchy disease, ileal inflammation, extracolonic inflammation, granulomatous inflammation in response to ruptured crypts, aphthous ulcers, or transmural inflammation. Furthermore, other forms of colitis, such as microscopic colitis, diverticulitis and diversion colitis may, on occasion, also show IBD-like changes. The clinical and pathological features that aid in the distinction between these entities, and others, are covered in detail in this review.     

Lymphoid follicular hyperplasia–a distinctive feature of diversion colitis

Diversion colitis refers to the inflammatory changes that occur in the defunctioned segment of the large intesting following diversion of the faecal stream. We report the histological features in the defunctioned rectums from seven patients: one each with severe constipation and Behcet's disease, two with Crohn's disease with rectal sparing and three with ulcerative colitis. The appearances of diversion colitis in a previously normal rectum are compared with diversion colitis with superimposed inflammatory bowel disease. Lymphoid follicular hyperplasia was found in all cases. This was marked in patients with inflammatory bowel disease. with or without initial rectal involvement. Other changes comprised surface epithelial degeneration and ulceration, mucosal inflammation including crypt abscesses, and crypt branching. Inflammatory and crypt changes were mild, except in ulcerative colitis where changes were marked and resembled those of the proximal colon. Lymphoid hyperplasia is a distinctive feature in diversion colitis. The term follicular proctitis, previously used to indicate chronic ulcerative colitis exclusively, should be re-examined.     

Mucosal capillary thrombi in rectal biopsies

We studied the initial rectal biopsy from 46 patients in whom subsequent follow-up established the diagnosis of either self-limited colitis or inflammatory bowel disease. An additional 12 non-inflamed rectal biopsies were also studied. There was between 2 and 8 years of follow-up in each of these cases. Staining for fibrin (MSB, fibrinogen), platelets (factor XIIIA, Y2/51), and capillary basement membrane (reticulin, collagen 4) was performed to identify thrombotic material within capillaries. Mucosal capillary thrombi were best identified by staining for factor XIIIA; thrombi were observed in 8/13 cases of ulcerative colitis, 4/10 cases of Crohn's disease, 1/3 cases of unspecified inflammatory bowel disease and 5/20 cases of self-limited colitis. The presence of capillary thrombi was not related to the severity of inflammation, but none of the control biopsies showed capillary thrombi. Their presence seems of little diagnostic value in distinguishing inflammatory bowel disease from self-limited colitis. The pathogenetic significance of these mucosal capillary thrombi is uncertain.     

The mucosal changes and pathogenesis of pneumatosis cystoides intestinalis

The clinical and pathologic findings in 11 patients with pneumatosis cystoides intestinalis (PCI) are described. Symptoms were variable but localized to the gastrointestinal tract. Only one patient had obstructive airway disease. Although gas cysts of varying sizes were present in the colonic wall in all cases, distinctive changes were also observed in the mucosa. Architectural disturbances were seen in 11 of 13 specimens, and changes mimicking those of inflammatory bowel disease, including cryptitis, crypt abscesses, chronic inflammation, and granulomas, were present. In addition, crypt dilation and partial crypt rupture, with formation of intramucosal cysts, were seen in association with clusters of small gas cysts in the lamina propria. The transgression of gas cysts through the muscularis mucosae and the presence of larger giant cell-lined cysts in the submucosa suggested entry of gas generated in the colonic lumen or within inflamed crypts from the mucosal aspect. Other postulated pathogeneses of PCI are discussed.     

Microscopic colitis with giant cells

AIMS: Collagenous colitis and lymphocytic colitis are the two types of microscopic colitis with specific morphological features. In this report we describe a new histopathological subtype of microscopic colitis. METHODS AND RESULTS: Colonoscopy in four patients with chronic watery diarrhoea showed no macroscopic abnormalities. The random biopsies from the colon showed subepithelial multinucleated giant cells in combination with the features of collagenous colitis in three patients and lymphocytic colitis in one patient. These multinucleated giant cells were positive for CD68. The density of macrophages was highest in the most superficial part of the lamina propria. In one patient, a previous biopsy showed features consistent with collagenous colitis without multinucleated giant cells. Treatment with budesonide led to the disappearance of diarrhoea in all four patients. CONCLUSIONS: The clinical and histopathological features of the four presented patients indicate that there exists a histopathological subtype of microscopic colitis characterized by the presence of subepithelial multinucleated giant cells, which probably arise from fusion of subepithelial macrophages. Analysis of more patients with this histopathological subtype of microscopic colitis is necessary to determine whether they also form a clinically distinct group.     

Focal active colitis: a prospective study of clinicopathological correlations in 90 patients

Shetty S, Anjarwalla S M, Gupta J, Foy C J W, Shaw I S, Valori R M & Shepherd N A
(2011) Histopathology 59 , 850–856 Focal active colitis: a prospective study of clinicopathological correlations in 90 patients Aims: Considerable controversy exists about the clinical implication of a diagnosis of focal active colitis (FAC). The aim of this study was to assess clinicopathological correlations of FAC in 90 adults, representing the largest and only prospective series of FAC. Methods and results: Patients were assessed by comprehensive clinical follow‐up and questionnaires. Fifteen histopathological features were scored and correlated with clinical outcome. In 24% of patients drugs, especially NSAIDs, were implicated. Infection was a probable cause in 19%. In 14 patients (15.6%), predominantly women, a diagnosis of chronic inflammatory bowel disease was ultimately made. Most were Crohn’s disease, but this is the first study in which FAC has presaged an ultimate diagnosis of ulcerative colitis in adults (in two patients). A specific subtype of FAC, termed basal FAC, was significantly associated with drugs. These excepted, this study has found no histopathological parameters of FAC, such as amount, location and/or distribution, to correlate with clinical outcome or allowed selection of those patients more likely to show subsequent evidence of chronic inflammatory bowel disease. Conclusion: This study has provided powerful information on the implication of a diagnosis of FAC. In a small but not inconsiderable case number, the ultimate diagnosis will be chronic inflammatory bowel disease.     

Are metaplasias in colorectal adenomas truly metaplasias?

Five thousand seven hundred seventy-eight adenomas or adenomas containing carcinoma from 3215 patients were examined by routine histologic methods for the presence of epithelial metaplasias. Three forms of epithelial metaplasia were encountered: squamous cell metaplasia (0.44%), Paneth cell metaplasia (0.20%), and melanocytic metaplasia (0.017%). In several instances multiple forms of metaplasia were encountered in the same polyp. In those cases in which the paraffin blocks were available, a Grimelius stain was performed. Grimelius-positive cells were present in 63% of the adenomas containing a metaplastic cell type. All cases with Paneth cell differentiation were immunoreactive for lysozyme; all lesions containing areas of squamous differentiation were immunoreactive for keratin except 2. The histopathologic features of these cases are discussed, and it is concluded that rather than representing a true metaplastic process, Paneth cell, squamous cell, and melanocyte differentiation represent the full range of cellular differentiation that endodermally derived tissues can exhibit, particularly when they undergo neoplastic alterations.