The Endoscopically Normal Colon: Is Biopsy Justifiable?
The Endoscopically Normal Colon: Is Biopsy Justifiable?
Objective Mapping biopsy of endoscopically normal colon is a contentious area and generates considerable work for histopathology services. Managing demand for pathological testing is a current healthcare priority. In this retrospective audit, the authors aimed to establish diagnostic yield of mapping biopsy in this specific subgroup and identify situations where practice could be safely streamlined.
Design Cases were retrieved over a 10-month period. Histopathology results were correlated with relevant endoscopy reports. The data were anonymised and analysed.
Setting Department of Cellular Pathology, Southampton General Hospital, UK.
Results 717 cases were retrieved. 308 (43%) cases were reported as endoscopically normal. 278 (90%) cases with endoscopically normal/near normal mucosa showed normal/near normal histology. 30/308 (9.7%) endoscopically normal cases showed pathological abnormalities. 9/308 (2.9%) cases of microscopic colitis were detected. Of the 30 cases with pathological abnormalities, 20 (66.7%) presented with change in bowel habit and 6 (20%) had a pre-existing diagnosis of inflammatory bowel disease.
Conclusions Pathological abnormalities in endoscopically normal colon are found most frequently in those who present with change in bowel habit or a known history of inflammatory bowel disease. The authors support biopsy in these individuals and believe that mapping biopsy of endoscopically normal colon in patients referred for other reasons (eg, bright red rectal bleeding or iron deficiency anaemia) should not be performed routinely as diagnostic yields are very low. Guidelines on appropriate use of mapping biopsy in this setting are limited. Streamlining patients based on reason for referral or presenting symptoms may be a useful step towards more effective management of histopathological demand.
Endoscopic colonic mapping biopsies are widely used as a diagnostic tool in the investigation of inflammatory bowel pathology and represent a significant proportion of the workload of any gastrointestinal histopathology service. Mapping biopsy of the colon involves a series of multiple mucosal biopsies taken sequentially from proximal to distal. In a full colonoscopy this may include biopsies from terminal ileum, caecum, ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid and rectum. In sigmoidoscopy, the biopsies are limited to the left side of the colon. The role of biopsy in the endoscopically normal colorectum is an area of contention. Although it is firmly established that certain pathology, for example, microscopic colitis (lymphocytic colitis and collagenous colitis) and Crohn's disease may occur in endoscopically normal mucosa, the reported rates of histological diagnoses made from seemingly normal mucosa vary widely, between 3% and 32.1% in previously published studies.
Exclusion of microscopic colitis is a common reason for mapping biopsies to be taken during an endoscopically normal sigmoidoscopy or colonoscopy. The Royal College of Pathologists commented in their document 'Histopathology and cytopathology of limited or no clinical value' that endoscopic biopsy of the normal colon should only be performed in patients in the correct clinical setting with a history of persistent watery diarrhoea without blood. The British Society of Gastroenterology in association with the Joint Advisory Group in Gastrointestinal Endoscopy state in their document 'Quality and Safety Indicators for Endoscopy' that biopsies should be performed in 100% of individuals with persistent diarrhoea.
Abstract and Introduction
Abstract
Objective Mapping biopsy of endoscopically normal colon is a contentious area and generates considerable work for histopathology services. Managing demand for pathological testing is a current healthcare priority. In this retrospective audit, the authors aimed to establish diagnostic yield of mapping biopsy in this specific subgroup and identify situations where practice could be safely streamlined.
Design Cases were retrieved over a 10-month period. Histopathology results were correlated with relevant endoscopy reports. The data were anonymised and analysed.
Setting Department of Cellular Pathology, Southampton General Hospital, UK.
Results 717 cases were retrieved. 308 (43%) cases were reported as endoscopically normal. 278 (90%) cases with endoscopically normal/near normal mucosa showed normal/near normal histology. 30/308 (9.7%) endoscopically normal cases showed pathological abnormalities. 9/308 (2.9%) cases of microscopic colitis were detected. Of the 30 cases with pathological abnormalities, 20 (66.7%) presented with change in bowel habit and 6 (20%) had a pre-existing diagnosis of inflammatory bowel disease.
Conclusions Pathological abnormalities in endoscopically normal colon are found most frequently in those who present with change in bowel habit or a known history of inflammatory bowel disease. The authors support biopsy in these individuals and believe that mapping biopsy of endoscopically normal colon in patients referred for other reasons (eg, bright red rectal bleeding or iron deficiency anaemia) should not be performed routinely as diagnostic yields are very low. Guidelines on appropriate use of mapping biopsy in this setting are limited. Streamlining patients based on reason for referral or presenting symptoms may be a useful step towards more effective management of histopathological demand.
Introduction
Endoscopic colonic mapping biopsies are widely used as a diagnostic tool in the investigation of inflammatory bowel pathology and represent a significant proportion of the workload of any gastrointestinal histopathology service. Mapping biopsy of the colon involves a series of multiple mucosal biopsies taken sequentially from proximal to distal. In a full colonoscopy this may include biopsies from terminal ileum, caecum, ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid and rectum. In sigmoidoscopy, the biopsies are limited to the left side of the colon. The role of biopsy in the endoscopically normal colorectum is an area of contention. Although it is firmly established that certain pathology, for example, microscopic colitis (lymphocytic colitis and collagenous colitis) and Crohn's disease may occur in endoscopically normal mucosa, the reported rates of histological diagnoses made from seemingly normal mucosa vary widely, between 3% and 32.1% in previously published studies.
Exclusion of microscopic colitis is a common reason for mapping biopsies to be taken during an endoscopically normal sigmoidoscopy or colonoscopy. The Royal College of Pathologists commented in their document 'Histopathology and cytopathology of limited or no clinical value' that endoscopic biopsy of the normal colon should only be performed in patients in the correct clinical setting with a history of persistent watery diarrhoea without blood. The British Society of Gastroenterology in association with the Joint Advisory Group in Gastrointestinal Endoscopy state in their document 'Quality and Safety Indicators for Endoscopy' that biopsies should be performed in 100% of individuals with persistent diarrhoea.