Two From the Ascending Colon and Two From the Descending Colon: Biopsies From Microscopic Colitis Simplified
Douglas K. Rex, MD, FASGE, reviewing Virine, B, et al. Clin Gastroenterol Hepatol 2020 Feb 25.
Guidelines recommend that clinicians perform 8 biopsies total from the right and left sides of the colon to diagnose microscopic colitis (MC) in patients with recurrent watery diarrhea. Flexible sigmoidoscopy has been advocated as an alternative to colonoscopy, but biopsy specimens obtained from only the left side of the colon have slightly impaired sensitivity.
In a study of 101 consecutive patients with microscopic colitis (collagenous colitis, n=52; lymphocytic colitis, n=42; and both, n=7), the diagnostic sensitivity of biopsy samples from specified sites were highest for MC in the ascending colon (97%), transverse colon (96%), and sigmoid colon (91%). In 39 cases for which there were biopsy samples from both the ascending and descending colon, the specimens were positive for MC in 95% of the samples from the ascending colon, 82% of the specimens from the descending colon, and 100% of the samples from one or the other.
COMMENT
These data indicate that a simplified biopsy program of two specimens from the ascending colon and two from the descending colon could have 100% sensitivity for microscopic colitis. This is helpful as it could simplify the biopsy protocol and speed it up a bit in patients with suspected microscopic colitis.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
Douglas K. Rex, MD, FASGE
CITATION(S)
Virine, B, Chande N, Driman DK. Biopsies from ascending and descending colon are sufficient for diagnosis of microscopic colitis. Clin Gastroenterol Hepatol 2020 Feb 25. (Epub ahead of print) (https://doi.org/10.1016/j.cgh.2020.02.036)
