British Society of Gastroenterology position statement on serrated polyps in the colon and rectum

Serrated polyps have been recognised in the last decade as important premalignant lesions accounting for between 15% and 30% of colorectal cancers. There is therefore a clinical need for guidance on how to manage these lesions; however, the evidence base is limited. A working group was commission by the British Society of Gastroenterology (BSG) Endoscopy section to review the available evidence and develop a position statement to provide clinical guidance until the evidence becomes available to support a formal guideline. The scope of the position statement was wide-ranging and included: evidence that serrated lesions have premalignant potential; detection and resection of serrated lesions; surveillance strategies after detection of serrated lesions; special situations-serrated polyposis syndrome (including surgery) and serrated lesions in colitis; education, audit and benchmarks and research questions. Statements on these issues were proposed where the evidence was deemed sufficient, and re-evaluated modified via a Delphi process until >80% agreement was reached. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool was used to assess the strength of evidence and strength of recommendation for finalised statements. Key recommendation: we suggest that until further evidence on the efficacy or otherwise of surveillance are published, patients with sessile serrated lesions (SSLs) that appear associated with a higher risk of future neoplasia or colorectal cancer (SSLs ≥10 mm or serrated lesions harbouring dysplasia including traditional serrated adenomas) should be offered a one-off colonoscopic surveillance examination at 3 years (weak recommendation, low quality evidence, 90% agreement).

Rapid infrared mapping for highly accurate automated histology in Barrett's oesophagus.

Barrett's oesophagus (BE) is a premalignant condition that can progress to oesophageal adenocarcinoma. Endoscopic surveillance aims to identify potential progression at an early, treatable stage, but generates large numbers of tissue biopsies. Fourier transform infrared (FTIR) mapping was used to develop an automated histology tool for detection of BE and Barrett's neoplasia in tissue biopsies. 22 oesophageal tissue samples were collected from 19 patients. Contiguous frozen tissue sections were taken for pathology review and FTIR imaging. 45 mid-IR images were measured on an Agilent 620 FTIR microscope with an Agilent 670 spectrometer. Each image covering a 140 µm × 140 µm region was measured in 5 minutes, using a 1.1 µm2 pixel size and 64 scans per pixel. Principal component fed linear discriminant analysis was used to build classification models based on spectral differences, which were then tested using leave-one-sample-out cross validation. Key biochemical differences were identified by their spectral signatures: high glycogen content was seen in normal squamous (NSQ) tissue, high glycoprotein content was observed in glandular BE tissue, and high DNA content in dysplasia/adenocarcinoma samples. Classification of normal squamous samples versus 'abnormal' samples (any stage of Barrett's) was performed with 100% sensitivity and specificity. Neoplastic Barrett's (dysplasia or adenocarcinoma) was identified with 95.6% sensitivity and 86.4% specificity. Highly accurate pathology classification can be achieved with FTIR measurement of frozen tissue sections in a clinically applicable timeframe.

European consensus on the histopathology of inflammatory bowel disease.

The histologic examination of endoscopic biopsies or resection specimens remains a key step in the work-up of affected inflammatory bowel disease (IBD) patients and can be used for diagnosis and differential diagnosis, particularly in the differentiation of UC from CD and other non-IBD related colitides. The introduction of new treatment strategies in inflammatory bowel disease (IBD) interfering with the patients' immune system may result in mucosal healing, making the pathologists aware of the impact of treatment upon diagnostic features. The European Crohn's and Colitis Organisation (ECCO) and the European Society of Pathology (ESP) jointly elaborated a consensus to establish standards for histopathology diagnosis in IBD. The consensus endeavors to address: (i) procedures required for a proper diagnosis, (ii) features which can be used for the analysis of endoscopic biopsies, (iii) features which can be used for the analysis of surgical samples, (iv) criteria for diagnosis and differential diagnosis, and (v) special situations including those inherent to therapy. Questions that were addressed include: how many features should be present for a firm diagnosis? What is the role of histology in patient management, including search for dysplasia? Which features if any, can be used for assessment of disease activity? The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas.

Gastric schwannoma: a benign tumour often mistaken clinically, radiologically and histopathologically for a gastrointestinal stromal tumour--a case series.

INTRODUCTION: Gastric schwannomas are rare mesenchymal tumours that arise from the nerve plexus of the gut wall. They present with non-specific symptoms and are often detected incidentally. Pre-operative investigation is not pathognomonic and many are therefore diagnosed as gastrointestinal stromal tumours (GISTs). Operative resection is usually curative as they are almost always benign, underpinning the importance of differentiating them from GISTs. METHODS: Three cases of gastric schwannomas were identified over a seven-year period. The clinical details and management were reviewed retrospectively. RESULTS: There were two women and one man with a mean age of 62 years (range: 51-69 years). Two patients presented with bleeding and one with abdominal pain. The mean tumour size was 5.2 cm (range: 2-10 cm) and the tumours were resected completely following total or wedge gastrectomies. Histology in all cases showed spindle cells with a cuff of lymphoid tissue. Immunohistochemistry confirmed positive S100 staining and negative CD117 and DOG-1 staining in all cases. CONCLUSIONS: We report our experience with these unusual primary stromal tumours of the gut and their presentations, pre-operative investigations, operative findings and pathological findings are discussed. Operative resection in all cases has been considered curative, which is supported by previous series confirming the excellent prognosis of gastric schwannomas.

Current management of Barrett's oesophagus.

Barrett's oesophagus is one of the most common pre-malignant conditions in the world and its incidence is increasing. The management of this disease is currently the subject of research and debate, with medical, endoscopic and operative intervention all having a therapeutic role.

Intranodal neurilemmoma presenting as parotid mass.

OBJECTIVE: We report a case of benign intranodal neurilemmoma, an extremely rare tumour arising from a nerve sheath within a lymph node. CASE REPORT: A 67-year-old woman underwent surgery for a left-sided parotid mass. Histopathological analysis revealed a tumour arising from a lymph node within the superficial lobe of the parotid gland. The tumour demonstrated histological features of an intranodal neurilemmoma. CONCLUSIONS: This case represents the first report of an intranodal neurilemmoma arising within a parotid lymph node, and supports the proposal that intranodal neurilemmoma be recognised as a distinct histological entity.

Polypoid mucosal prolapse complicating low rectal adenomas: beware the inflammatory cloacogenic polyp!

AIMS: Polypoid mucosal prolapse near the anorectal junction mimics adenomas endoscopically and histopathologically. The aim was to describe the phenomenon of polypoid mucosal prolapse arising secondary to adenomas at the anorectal junction. METHODS AND RESULTS: Four cases of low rectal adenoma with polypoid mucosal prolapse were assessed histopathologically, as well as with p53 and Ki67 antibodies. Two were male and two female; the mean age was 45 years. Available follow-up has revealed no recurrence in any patient. All cases showed mucosal expansion with ulceration or erosion, crypt architectural irregularity, fibromuscular proliferation between crypts and variable epithelial serration and inflammation. Each case also showed unequivocal dysplasia, often co-mingled with features of prolapse, highlighted by p53 and Ki67 immunohistochemistry, which demonstrated positivity within dysplastic areas. CONCLUSIONS: Histopathologists must recognize the potential for adenomatous/dysplastic foci in anorectal lesions to superficially resemble inflammatory cloacogenic polyps. We recommend use of immunomarkers p53 and Ki67 to aid the interpretation of challenging cases. We believe that polypoid mucosal prolapse changes can be a secondary phenomenon, due to adenomas close to or at the anorectal junction.

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.

Basiliximab for the treatment of steroid-resistant ulcerative colitis: further experience in moderate and severe disease.

BACKGROUND: Preliminary data have suggested that interleukin-2 receptor blockade with basiliximab may increase steroid sensitivity. We have previously reported a small case series demonstrating the potential of basiliximab as a novel agent for the treatment of steroid-resistant ulcerative colitis. AIM: To report further experience of the efficacy and safety of treatment with the interleukin-2 receptor blocking monoclonal antibody basiliximab, in addition to steroids, for the treatment of severe and moderate steroid-resistant ulcerative colitis. METHODS: Twenty patients were enrolled - 13 patients with moderate steroid-resistant ulcerative colitis (Ulcerative Colitis Symptom Score: >or=6) and seven patients with severe steroid-resistant ulcerative colitis. All were given a single dose of 40 mg basiliximab plus standard steroid therapy in an open-label, uncontrolled trial. Primary end point was clinical remission within 8 weeks (Ulcerative Colitis Symptom Score:

Serosal involvement in gastrointestinal cancer: its assessment and significance.

There is an increasing burden upon diagnostic histopathologists to identify accurately factors of prognostic and therapeutic implication in gastrointestinal cancer. It is perhaps partly because of the use of rigid sequential staging systems, such as the Dukes' classification, that some factors, perhaps most notably involvement of surgical margins (especially in rectal cancer) and serosal involvement (particularly in oesophageal, colonic and rectal cancer), have been relatively neglected until more recently. This is surprising and concerning because both of these pathologically derived parameters strongly correlate with subsequent locoregional recurrence and, ultimately, with prognosis. Whilst the occurrence and significance of serosal involvement have been well recognized in gastric cancer for many years, relatively little attention has been paid to the phenomenon in oesophageal cancer and yet both pleural and peritoneal involvement may be comparatively commonly identified in oesophageal cancer. Serosal involvement and transperitoneal spread are also of considerable prognostic importance in primary appendiceal carcinoma. Only more recently has the significance of serosal involvement been appreciated in colonic and rectal cancer. In the colon, the phenomenon is now recognized to be one of the most important factors in predicting transperitoneal spread and overall prognosis. Furthermore, there is increasing interest in alternative novel strategies, including intraperitoneal chemotherapy and radical peritoneal surgery, as legitimate therapeutic options in many gastrointestinal cancers.

Lymph node harvests directly influence the staging of colorectal cancer: evidence from a regional audit.

AIMS: To assess the quality of histopathology reporting and accuracy of Dukes's staging of colorectal cancers in the former South Western Health region and to determine the impact of numbers of lymph nodes examined on stage ascription. METHODS: Histopathology reports of colorectal cancer for 1993-7 were analysed. Completeness was assessed regarding reported numbers of lymph nodes examined, numbers found positive, Dukes's stage, and ICD9 code. Numbers of lymph nodes examined, numbers found positive, and Dukes's stage were recorded. Results from one hospital known to have high standards of reporting were compared with those from elsewhere. RESULTS: In total, 629 reports were examined from the reference hospital and 918 from elsewhere. Fewer than one in 20 (4.3%) reports from the reference hospital were incomplete, compared with a third (36.1%) elsewhere. The average number of nodes examined for each case at the reference hospital was 18.81 and 6.41 elsewhere. The average number of positive nodes for each case was 2.47 at the reference hospital and 1.15 elsewhere. The proportion of Dukes's stage C cases was significantly higher at the reference hospital than elsewhere. Ascertainment of Dukes's stage C cases was related to number of lymph nodes examined, with optimal ascertainment levels when at least 10 and fewer than 15 nodes were examined. CONCLUSIONS: Standards of histopathology reporting, and ascertainment of Dukes's stage C, were significantly higher at the reference hospital. Variations in ascertainment levels of Dukes's stage C disease mainly resulted from variations in the numbers of lymph nodes examined.

Epstein-Barr virus infection in colorectal neoplasms associated with inflammatory bowel disease: detection of the virus in lymphomas but not in adenocarcinomas.

Epstein-Barr virus (EBV) is associated with several lymphoid and epithelial human malignancies. The latter include gastric adenocarcinomas, while sporadic colorectal adenocarcinomas (CRCs) have been reported to be EBV-negative. Recently, increased numbers of EBV-infected B lymphocytes have been detected in intestinal mucosal samples affected by ulcerative colitis (UC) and, to a lesser extent, Crohn's disease (CD). Both CRC and colorectal non-Hodgkin's lymphoma (NHL) are recognized complications of inflammatory bowel disease (IBD), but it is unclear to what extent EBV contributes to the development of these neoplasms. Seventeen cases of IBD-associated CRC and nine cases of IBD-associated colorectal NHL were therefore studied for the presence of EBV by in situ hybridization. EBV-positive cases were further studied for the expression of the EBV-encoded nuclear antigen (EBNA) 2 and the latent membrane protein (LMP) 1 of EBV by immunohistochemistry. Four out of seven cases of colorectal NHL associated with UC were shown to be EBV-positive. In addition, two of two colorectal NHLs developing in patients with CD were EBV-positive. Of the EBV-positive lymphomas, three displayed a pattern of EBV latent gene expression consistent with type I latency (EBNA2(-)/LMP1(-)), two a type II pattern (EBNA2(-)/LMP1(+)), and one a type III pattern (EBNA2(+)/LMP1(+)). These findings suggest that EBV infection is involved in the pathogenesis of a proportion of colorectal NHLs developing in IBD. Iatrogenic immunosuppression may contribute to the development of these lymphomas. By contrast, all 17 IBD-associated CRCs were EBV-negative, including a case of CRC occurring synchronously with an EBV-positive NHL. In conjunction with previous reports on sporadic CRCs, this suggests that EBV is not involved in the pathogenesis of CRC.

Basiliximab (anti-CD25) in combination with steroids may be an effective new treatment for steroid-resistant ulcerative colitis.

BACKGROUND: Steroid resistance represents a major clinical problem in the treatment of ulcerative colitis. In vitro, interleukin-2 renders lymphocytes steroid resistant. AIM: To explore the therapeutic potential of interleukin-2 receptor blockade in steroid-resistant ulcerative colitis with both in vitro measures and a pilot in vivo study. METHODS: Ten patients with steroid-resistant ulcerative colitis received a single bolus of 40 mg of intravenous basiliximab plus steroid treatment in an open-label, uncontrolled, 24-week study. The outcome was assessed using the Ulcerative Colitis Symptom Score, rectal biopsy and Inflammatory Bowel Disease Questionnaire. Lymphocyte steroid sensitivity was measured in vitro in 39 subjects in the presence or absence of basiliximab. RESULTS: Nine of the 10 patients achieved clinical remission within 8 weeks. At 24 weeks, seven patients were in clinical remission. Marked improvement in the Ulcerative Colitis Symptom Score was seen by 1 week (P = 0.004) and on rectal biopsy and Inflammatory Bowel Disease Questionnaire by 2 weeks (both P < 0.05). Improvements persisted to 24 weeks (Ulcerative Colitis Symptom Score, Inflammatory Bowel Disease Questionnaire, both P < 0.005). Eight of the nine responders relapsed (median, 9 weeks), but remission was re-achieved with further corticosteroids and the addition of azathioprine. At 24 weeks, seven patients were in full clinical remission, five off all steroid therapy. In vitro measurement of lymphocyte steroid sensitivity demonstrated steroid resistance in 22% of subjects. All were rendered steroid sensitive in the presence of basiliximab. CONCLUSIONS: Basiliximab appears to be effective at inducing remission in steroid-resistant ulcerative colitis. In vitro, basiliximab also produced a dramatic increase in lymphocyte steroid sensitivity in healthy subjects. Confirmation in randomized controlled studies is required.

Colorectal mass lesions masquerading as chronic inflammatory bowel disease on mucosal biopsy.

AIMS: We bring to the attention of diagnostic pathologists a further cause of mimicry of chronic inflammatory bowel disease on mucosal biopsy, namely intramural and subserosal colorectal mass lesions. METHODS AND RESULTS: In a 10-year prospective study in one centre, we describe 26 cases in which the initial colonoscopic biopsies suggested a diagnosis of chronic inflammatory bowel disease, whereas subsequent information indicated that the mucosal changes were due to underlying mass lesions, without evidence of chronic inflammatory bowel disease. These mass lesions included underlying primary adenocarcinoma, metastatic carcinoma, pneumatosis, endometriosis and complicated diverticular disease. CONCLUSIONS: In the colon and rectum, intramural and subserosal mass lesions are a significant cause of chronic inflammatory bowel disease mimicry. Possible pathogenic mechanisms include mechanical effects, lymphatic obstruction by underlying tumour, relative mucosal ischaemia and mucosal prolapse. Since the changes seen on mucosal biopsies are a secondary phenomenon, we tentatively suggest that 'secondary colitis' may be an appropriate appellation.

Identification of objective pathological prognostic determinants and models of prognosis in Dukes' B colon cancer.

BACKGROUND AND AIMS: There is a need for objective easily determined pathological prognostic parameters in Dukes' B colon carcinoma to allow selection of such patients for further treatment as the role of adjuvant chemotherapy for these patients remains unclear. This study was initiated to assess the influence of pathological factors on prognosis in an unselected prospective series of Dukes' B colonic cancer. METHODS: The Gloucester Colorectal Cancer study, established in 1988, recruited more than 1000 cases. Meticulous pathological assessment of the 268 Dukes' B colonic cancer resections in this series included evaluation of all pathological factors that could influence staging and prognosis. All patients entered a comprehensive follow up system. RESULTS: Four pathologically determined factors--peritoneal involvement, venous spread (both submucosal and extramural), spread to involve a surgical margin, and perforation through the tumour-were independent prognostic factors in multivariate analysis. Combining these four factors into a simple cumulative scoring system generated clinically useful prognostic groups. CONCLUSIONS: The cumulative prognostic index allows apportionment of patients with Dukes' B colon cancer into defined prognostic groups, which in turn could allow more objective selection of patients for adjuvant therapy, especially as part of clinical trials.