Value of counting colonic mucosal Ig-containing cells in the differential diagnosis of chronic inflammatory bowel disease.

AIMS: To investigate whether counting cells containing immunoglobulin (Ig) subclass in colonic biopsy specimens of patients with chronic inflammatory bowel disease, in addition to conventional histological evaluation, can improve the differentiation of patients with Crohn's disease from those with ulcerative colitis. METHODS: The colonic and rectal biopsy specimens of 40 patients with chronic inflammatory bowel disease, comprising 20 patients with Crohn's disease and 20 with ulcerative colitis, were used and sections were stained specifically for IgA, IgM, and IgG heavy chains using an indirect immune peroxidase method. The immunoglobulin subclass containing cells were counted using an ocular grid counting method in a light microscope. A linear stepwise discriminant analysis was performed on Ig subclass containing cell counts in combination with 16 reproducible histological features. The results of this discriminant analysis were compared with the results of the discriminant analyses in which only the histological features were used. RESULTS: Applying stepwise discriminant analysis, two histological features (an excess of histiocytes in the lamina propria and the villous or irregular aspect of the mucosal surface) in combination with IgMax were selected as the most discriminatory parameters that distinguish Crohn's disease from ulcerative colitis. IgMmax was defined as the maximum value of the mean percentage of IgM containing cells over all the biopsy locations. The use of this combination resulted in a better classification in 20% of the patients with Crohn's disease and in 9% of the patients with ulcerative colitis compared with the use of histological features alone. CONCLUSIONS: Morphometric enumeration of Ig subclass containing cells in colonic mucosal biopsy specimens has diagnostic value as a means of differentiating individual patients with Crohn's disease from those with ulcerative colitis.

Long-term risk of colorectal cancer after excision of rectosigmoid adenomas.

BACKGROUND AND METHODS: Surveillance by repeated colonoscopy is currently recommended for patients with colorectal adenomas. We assessed the long-term risk of colorectal cancer after rigid-instrument sigmoidoscopy and polypectomy in 1618 patients with rectosigmoid adenomas (tumor of the rectum or distal sigmoid colon) who did not undergo surveillance. A total of 22,462 person-years of observation were accrued (mean, 14 years per patient). RESULTS: The incidence of subsequent rectal cancer in these patients was similar to that in the general population (standardized incidence ratio, 1.2; 95 percent confidence interval, 0.7 to 2.1). Most rectal cancers developed in patients whose adenomas had been inadequately removed; the risk was very low after complete removal. The risk of subsequent colon cancer depended on the histologic type, size, and number of adenomas in the rectosigmoid. Among 842 patients with a rectosigmoid adenoma that was tubulovillous, villous, or large (greater than or equal to 1 cm), colon cancer developed in 31 patients. The standardized incidence ratio was 3.6 (95 percent confidence interval, 2.4 to 5.0) overall and 6.6 (95 percent confidence interval, 3.3 to 11.8) if there were multiple rectosigmoid adenomas. Among the remaining 776 patients with only small, tubular adenomas (whether single or multiple), colon cancer developed in only 4 patients. The standardized incidence ratio in this group was 0.5 (95 percent confidence interval, 0.1 to 1.3). CONCLUSIONS: Follow-up colonoscopic examinations may be warranted in patients with tubulovillous, villous, or large adenomas in the rectosigmoid, particularly if the adenomas are also multiple. In patients with only a single, small tubular adenoma that is only mildly or moderately dysplastic (43 percent of our series), however, surveillance may not be of value because the risk of cancer is so low.

Histopathological evaluation of colonic mucosal biopsy specimens in chronic inflammatory bowel disease: diagnostic implications.

In a prospective blind evaluation of multiple colonic mucosal biopsy specimens, 45 clinically well defined patients with chronic inflammatory bowel disease (21 Crohn's disease and 24 ulcerative colitis) and 16 control subjects (seven normal subjects and nine patients with diverticular disease) were studied to identify reproducible histopathological features which could distinguish chronic inflammatory bowel disease (CIBD) from non-CIBD and Crohn's disease from ulcerative colitis. Using kappa statistics 16 of 41 histological features were sufficiently reproducible for further stepwise discriminant analysis to differentiate between CIBD and non-CIBD, and between Crohn's disease and ulcerative colitis. Using the combination of three features (an increase of lymphocytes and plasma cells in the lamina propria, the presence of branching of crypts, and neutrophils in the crypt epithelium) we were able to distinguish CIBD from non-CIBD in 89% of the cases with high probability (p greater than 0.85). To separate Crohn's disease from ulcerative colitis three features (an excess of histiocytes in combination with a villous or irregular aspect of the mucosal surface and granulomas) had a high predictive value. Using these features 70% of Crohn's disease patients and 75% of ulcerative colitis patients were correctly classified with a high probability (p greater than 0.85). These findings indicate that the pathologist is dependent on the presence of only a few histological features for a reliable classification of Crohn's disease and ulcerative colitis.

Precancer and cancer in extensive ulcerative colitis: findings among 401 patients over 22 years.

Patients with extensive ulcerative colitis who do not need early surgery have been offered regular examination with the aim of detecting precancerous change (dysplasia) or early colorectal carcinoma. Outpatient visits with clinical examination, sigmoidoscopy, and biopsy were supplemented by two-yearly colonoscopy after the disease course reached 10 years. During the 22 year period from the beginning of 1966 to the end of 1987, 401 patients entered the programme and together contributed 4048 patient-years of observation. Apart from nine patients who left the country, follow up is complete until 1986 or 1987. Colorectal carcinoma developed in 22 patients and, in a further 12, biopsy evidence of precancer, described as severe/high grade dysplasia, was confirmed in a colectomy specimen. The cumulative probability of developing carcinoma was 3% at 15 years, 5% at 20 years, and 9% at 25 years; corresponding figures for precancer or carcinoma, or both were 4%, 7%, and 13%. Five patients died of colorectal carcinoma, two while under regular observation and three after developing carcinoma four to six years after their last attendance. Among the 17 patients who developed carcinoma while under observation, the Dukes stage was A or B in 12. Patients with extensive colitis whose disability does not warrant early surgery have a clinically important cancer risk after the disease has been present for 10 years. Our results suggest that follow up in the manner described reduces the mortality from this complication. Further work is needed to define the optimum method of surveillance and show if it is cost effective.

Primary malignant lymphoma of the large intestine complicating chronic inflammatory bowel disease.

Ten cases of malignant lymphoma of the colon and rectum complicating chronic inflammatory bowel disease are presented. Seven patients had chronic ulcerative colitis with a history varying from 6 to 20 years. There was extensive colitis in six of these patients and left-sided colitis in one. All seven lymphomas showed the pathological and immunohistological features of primary B-cell tumours of the gastrointestinal tract with a predominance of high-grade tumours. Three patients had Crohn's disease of the large intestine complicated by malignant lymphoma of the sigmoid colon or rectum. The history of Crohn's disease varied from 30 months to 20 years and in each case there was fissuring and fistulae. There was extensive anal involvement in two cases. Histologically the three lymphomas were heterogeneous: one was of 'granulomatous' T-cell type and the other two were markedly polymorphic and of equivocal phenotype. They were also characterized by numerous multinucleate tumour giant cells. Primary colorectal malignant lymphoma should be regarded as a rare, but significant, complication of ulcerative colitis. Immunosuppression may be an additional factor in the genesis of intestinal lymphoma in Crohn's disease. The prognosis appears to be dependent on factors already known to be of prognostic significance in primary gut lymphomas: a predominance of high-grade tumours suggests that the outlook is generally worse than that for idiopathic primary large intestinal lymphoma.

Observer study of the grading of dysplasia in ulcerative colitis: comparison with clinical outcome.

Patients with extensive ulcerative colitis are entered into surveillance programs that aim to detect premalignant changes. Biopsy specimens have been collected in the St Mark's Hospital (London) surveillance program over a 22-year-period. Specimens from patients reported as having dysplasia were reexamined. A total of 207 biopsy specimens from 86 patients were graded by five experienced pathologists according to the severity of the dysplasia. The overall agreement between the pathologists grading the specimens was poor; each pair agreed on between 42% and 65% of the slides. The best agreement was for slides that were said to show no dysplasia. Comparison with clinical outcome indicated that the pathologists most likely to diagnose dysplasia in patients with carcinoma were also likely to diagnose dysplasia in patients who did not go on to develop carcinoma. Calculating an average grade of dysplasia did not significantly improve diagnostic accuracy. Despite the findings of this interobserver study, dysplasia has been a successful marker in clinical practice. Pathologists should ensure that they have access to previous slides from the same patient and adequate clinical information before reporting biopsies as positive for dysplasia. An additional biopsy should usually be undertaken before surgery is considered.

Juvenile polyposis--a precancerous condition.

Clinical and pathological findings in 87 patients with juvenile polyposis have been reviewed; 1032 polyps were available from 80 of these patients; 840 were typical spherical juvenile polyps whereas 169 differed in being multilobulated or showing a villous configuration; 79 (46.7%) of the latter contained foci of epithelial dysplasia whereas only 76 (9.0%) of the typical juvenile polyps were dysplastic. The series also included 21 adenomas and two hyperplastic (metaplastic) polyps. The demonstration of dysplasia provides a histogenetic mechanism for the evolution of colorectal cancer from hamartomatous polyps; 18 juvenile polyposis patients have developed colorectal cancer at a mean age of 34 years (range 15-59). The clinical outcome was generally poor. No clinical or pathological distinction could be made between polyposis patients with and without colorectal cancer. Thus, the development of cancer in juvenile polyposis appears to be a random event. A working definition of juvenile polyposis is provided: (1) more than five juvenile polyps of the colorectum; and/or (2) juvenile polyps throughout the gastrointestinal tract; and/or (3) any number of juvenile polyps with a family history of juvenile polyposis. It is suggested that the condition should be treated as seriously as familial adenomatous polyposis except that regular colonoscopic surveillance may obviate the need for prophylactic colectomy.

Infantile colitis: a manifestation of intestinal Behcet's syndrome.

A brother and sister of first cousin Pakistani parents presented with recurrent mouth ulcers and chronic diarrhoea in the neonatal period. Diarrhoea persisted in spite of treatment with oral prednisolone and sulphasalazine. Both children required subtotal colectomy with ileostomy. Histopathology of the resected colons was virtually identical and showed multiple deep "flask"-shaped ulcers, often penetrating to the serosa, in the presence of chronic inflammation, but without any of the characteristic histological features of Crohn's disease. The appearance closely resembled the colitis of Beh,cet's syndrome. Both children (aged 6 and 3.5 years, respectively) have continued to have recurrent perianal disease with intermittent bloody diarrhoea since the operation. Apart from the initial symptoms of oral aphthous ulcerations in both children, no other major criteria have developed so far. Intestinal Behçet's syndrome should be considered in the differential diagnosis of chronic inflammatory bowel disease in childhood.

The DNA content in cancer and dysplasia in chronic ulcerative colitis.

The nuclear DNA content was determined with a cytophotometric technique in colonic mucosa of 15 patients with long-standing ulcerative colitis. The epithelial lesions were classified into inactive colitis, low grade and high grade dysplasia and adenocarcinoma. The histogram pattern varied between narrow unimodal in quiescent colitis, broad unimodal in low grade dysplasia with some hypertetraploid values in three cases (27%) and aneuploid in 62.5% of the lesions with high grade dysplasia. In well-differentiated adenocarcinoma the histograms were broad unimodal, whereas the curves of moderately and poorly differentiated carcinomas were wider and aneuploid. The technique can be used for a prognostic purpose: in dysplastic lesions, the detection of aneuploidy is important because it is frequently found in the presence of invasion although it does not allow its prediction. Carcinomas with polyploid DNA distribution have a better outcome than tumours with aneuploid distribution.

Reporting colorectal cancer.

Reporting colorectal cancer comprises two phases: the careful collection of pathological data; and the division of patients into groups with differing prognoses. Dukes' classification of rectal cancer was the outcome of this dual approach. It evolved over many years, and full details of its final form were not published until 1958, towards the end of his career. Others modified the classification during its evolution, and numerous rival pathological and clinicopathological systems now exist. The resulting confusion that surrounds the Dukes classification may make it impossible to compare pathological findings and the results of treatment between different centres. The importance of meticulous dissection and examination of surgical specimens is emphasised and a simple set of recommendations made. It is shown how modern statistical methods may identify pathological variables that have independent clinical importance. On the basis of this information a new system of prognostic categorisation for patients receiving apparently curative surgery for rectal cancer has been developed, which is superior to the Dukes classification in that it can place many more patients into groups with clear prognostic implications.

Restorative proctocolectomy with ileal reservoir: pathological and histochemical study of mucosal biopsy specimens.

Mucosal biopsy specimens from the ileal reservoirs of 92 patients who had undergone restorative proctocolectomy (12 with familial adenomatous polyposis, 78 with ulcerative colitis, and two with functional bowel disease) were studied. Chronic inflammation was found in almost all, as was villous atrophy of varying severity. Other changes included pyloric metaplasia and mucosal prolapse. Acute inflammatory changes and ulceration were less common but, when present, corresponded to the clinical condition of "pouchitis". A grading system was devised to score acute and chronic inflammatory changes. There was a significant increase in acute inflammatory scores in ulcerative colitis compared with those in familial adenomatous polyposis, and pouchitis was present only in patients who had had ulcerative colitis; the morphological features of pouchitis are similar to those seen in the colorectal mucosa in ulcerative colitis. Histochemical studies of mucin in the reservoirs of mucosa showed that there may have been a change from small intestinal mucin to colonic mucin.

Malignant lymphoma with eosinophilia of the gastrointestinal tract.

Lesions of the gastrointestinal tract with massive tissue eosinophilia may present a difficult diagnostic problem. In a series of 250 gastrointestinal lymphomas drawn from the files of St Bartholomew's and St Mark's Hospitals there were 28 cases of a lymphoma with distinctive histological features, characterized by a massive tissue eosinophilia. Two of these tumours were present in the stomach and 26 in the small intestine. Eight of the latter were associated with coeliac disease. On low power examination a zoning phenomenon was regularly seen and fissuring ulceration, with perforation and fistula formation, was a common finding. The tumour cells were large and pleomorphic with irregular nuclear morphology and prominent nucleoli. Eosinophils were the predominant inflammatory cell associated with the lymphoma but plasma cells, epithelioid histiocytes and small lymphocytes were also present. Vascular changes were prominent. Involved lymph nodes showed gross expansion of the paracortex by tumour. Immunohistochemical studies showed that this lymphoma was probably of T-cell origin.