Random Colonic Biopsies in Diagnosing Microscopic Colitis: Low Yield High Cost
MS Ismail, O Aoko, G Kavanagh, L Brandon, R Flood, K Hazel, J Ryan, S Sengupta, J Keohane
Gastroenterology and Pathology Department, Our Lady of Lourdes Hospital Drogheda, Louth County Hospital Dundalk
Microscopic colitis has been increasingly recognized as a cause for chronic watery diarrhoea and is more common in females in their fifth to sixth decade of life - . This condition is diagnosed by taking random colonic biopsies from a macroscopically normal colon during colonoscopy. The cost of taking random colonic biopsies can reach up to £160 (€200) per patient.
This study aims to assess the pickup rate of microscopic colitis from random colonic biopsies that were taken in 2 endoscopy referral centres in the north east (OLOLH Drogheda and LCH Dundalk) over a two year period.
Histology results from random colonic biopsies were obtained from the pathology department in Our Lady of Lourdes Hospital from the period of January 2012 to December 2013. This was compared with colonoscopy results to ensure that only biopsies from a macroscopically normal colon were included in the analysis.
1050 patients had random colonic biopsies performed over the 2 year period. 30 (2.9%) patients showed non-specific colitis; 11 (1.1%) patients showed microscopic colitis while the rest were normal (96%). In the patients with microscopic colitis, 3 (27.3%) had lymphocytic colitis and 8 (72.7%) had collagenous colitis. Mean age of diagnosis of microscopic colitis is 56.5 (49 to 71) years. All 11 patients were females. All patients complained of diarrhoea which led to a colonoscopy.
The pickup rate of microscopic colitis from random colonic biopsies in this study is extremely low (1.1%). As per previous studies1-3 our patient group fits the demographic profile for microscopic colitis. The potential cost of doing indiscriminate biopsies in this study could have reached £160,000 (€200,000)4. Given the current economic climate it may be more financially beneficial to risk stratify our patients prior to taking random biopsies in order to diagnose microscopic colitis.