Filiform polyps and filiform polyp-like lesions are common in defunctioned or diverted colorectum resection specimens.

We describe filiform polyps (FPs) in a series of defunctioned rectums with diversion colitis. A 6-year search of all defunctioned rectal resection specimens revealed 8 cases with 17 macroscopically observed FPs. They occurred in 4 females and 4 males aged between 12 and 64 years. Four had defunctioning colostomies for ulcerative colitis, 3 for Crohn disease and 1 for diverticular disease. Multiple lesions were seen in 6 of 8 cases: 1 case having 4 FPs, 1 patient with 3 lesions, and 4 cases with 2 lesions. The FP varied in length from 4 to 11 mm; mean length was 7.8 mm. No evidence of mucosal prolapse was seen in any of the polypoid lesions. In 65 cases without grossly observed polypoid lesions, prominent mucosal polypoid projections in keeping with FP were seen in 47 cases. These were observed in nonulcerated sections and were histologically identical to the 17 macroscopically observed FPs ranging from 3 to 8 mm, and 3 to 5 such polypoid lesions were seen in 20 cases. We suggest that FP and FP-like lesions are commonly encountered in defunctioned resection specimens.