The histological features of intestinal spirochetosis in a series of 113 patients.

A multicenter retrospective review of cases diagnosed as spirochetosis was performed to determine the presenting symptoms and histological changes. A total of 113 cases were retrieved from the archives, consisting of 97 colorectal specimens and 16 appendices. In only 25 cases was the presenting symptom recorded as diarrhea. Of the colorectal specimens, 87 (90%) showed no mucosal abnormality (apart from the spirochetes); the other 10 showed mucosal inflammation but 6 of them had a diagnosis of another inflammatory disease process accounting for the inflammatory changes. Five appendices showed acute appendicitis; the other 11 were unremarkable. It is concluded that spirochetosis in an unselected general population is unlikely to be of pathological significance. Furthermore, if spirochetosis is observed in an inflamed biopsy, it is most likely to be an incidental finding.