A 66-year-old Japanese woman with systemic lupus erythematosus (SLE) presented with
chronic watery diarrhea, which began 8 months after SLE diagnosis. She was given oral
medications such as loperamide but they were unsuccessful. Finally she was admitted
for evaluation of the chronic diarrhea, which was then of 4 months’ duration. Colonoscopy
was performed and showed numerous crowded, small, dilated, circling or winding blood
vessels on the mucosal surface of the entire colon, but especially the transverse
colon, appearing like a spider web ([Fig. 1], [2]). A surprising finding was a 20-cm-long linear ulcer or scar-like area of mucosal
damage without bleeding in the descending colon ([Fig. 3]). Biopsies were taken from the cecum, ascending colon, transverse colon, the ulcer-like
lesion of the descending colon, the sigmoid colon, and the rectum. Histopathology
results indicated that all the biopsies contained a subepithelial collagen band, compatible
with a diagnosis of collagenous colitis ([Fig. 4]). The patient was started on oral mesalamine, which resulted in fewer bowel movements.
Finally her diarrhea ceased. Follow-up colonoscopy 2 months later revealed normal
colonic mucosal vessels and a clearly diminished linear scar-like lesion.
Fig. 1 Colonoscopy showing the crowded vascularity of the colonic mucosa.
Fig. 2 Close observation of the colonic mucosa showing the dilated, circling or winding blood
capillaries.
Fig. 3 Mucosa of the descending colon showing the linear ulcer or scar-like lesion.
Fig. 4 Biopsy showing subepithelial collagen deposits.
Collagenous colitis is a disease that generally presents with chronic diarrhea, but
without specific radiographic or endoscopic findings. Diagnosis is usually on the
basis of histopathological evidence of collagen bands in the subepithelium of the
colon [1]. Endoscopic images of collagenous colitis are rarely available today. A few previous
collagenous colitis case reports have described abnormal endoscopic findings, with
one report of a crowded tortuous vascular pattern in a Japanese woman [2] and another report of colonic linear laceration with bleeding in a Caucasian woman
[3]. This case report highlights the possibility of diagnosing collagenous colitis using
specific colonoscopic findings, a method that may become even more important given
the dramatic development of electronic endoscopy.
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