Endoscopic findings and clinicopathologic characteristics of colonic schistosomiasis: a report of 46 cases

Abstract

Aim: To make a retrospective analysis of endoscopy findings and clinicopathologic characteristics of colonic schistosomiasis in order to further improve our understanding of the disease and decrease its misdiagnosis.

Methods: Endoscopy findings and clinicopathologic characteristics of 46 intestinal schistosomiasis patients were retrospectively analyzed. All the patients underwent colonoscopy and all biopsy specimens stained with hematoxylin and eosin were observed under a light microscope.

Results: Of the 46 colonic schistosomiasis patients, 1 was diagnosed as acute schistosomal colitis, 16 as chronic schistosomal colitis and 29 as chronic active schistosomal colitis according to their endoscopic findings and pathology. Not all patients were suspected of or diagnosed as colonic schistosomiasis. Of the 12 misdiagnosed patients, 4 were misdiagnosed as ulcerative colitis, 1 as Crohn's disease, and 7 as ischemic colitis. The segments of rectum and sigmoid colon were involved in 29 patients (63.0%). Intact Schistosoma ova were deposited in colonic mucosa accompanying infiltration of eosinocytes, lymphocytes, and plasma cells in acute schistosomal colitis patients. Submucosal fibrosis was found in chronic schistosomal colitis patients. Among the 17 patients with a signal polyp, hyperplastic polyp, canalicular adenoma with a low-grade intraepithelial neoplastic change, tubulovillous adenoma with a high-grade intraepithelial neoplastic change were observed in 10, 5, and 2 patients, respectively. Eight out of the 46 patients were diagnosed as colonic carcinoma.

Conclusion: Endoscopy contributes to the diagnosis of colonic schistosomiasis although it is nonspecific. A correct diagnosis of colonic schistosomiasis can be established by endoscopy in combination with its clinicopathologic characteristics.

Figure 1

Endoscopic findings of schistosomal colonic disease. A: Congestive, edematous mucosa in rectum with purulent secretion in mixed colitis; B: Congestive and edematous mucosa of sigmoid colon and intestinal stricture in mixed colitis; C: Mucosal erosion, superficial ulcer and granular change in descending colon with invisible submucosal blood vessels in mixed colitis; D: Congestive, edematous and erosive mucosa in rectum with invisible submucosal blood vessels in mixed colitis; E: Coarse, congestive, ulcerative mucosa and intestinal stricture in descending colon in mixed colitis; F: Patchy congestion and vague vascular net in mucosa of sigmoid colon in mixed colitis; G: Vascular net like map of sigmoid colon in chronic colitis; H: Cobwebbed vessels in rectum in chronic colitis; I: Giant flat, lobulated polypus in rectum in chronic colitis; J: Giant polypus in sigmoid colon in chronic colitis.

Figure 2

Pathology of schistosomal colonic disease (HE staining). A: Chronic inflammation in rectal mucosa and calcified schistosomal ova around fibroplasia and foreign-body giant cell reaction in submucosa (original magnification × 100); B: Same view as A, at a different magnification (original magnification × 200); C: Chronic inflammation accompanying acute activity and deposited schistosomal ova in submucosa (original magnification × 200); D: Same view as A, at a different magnification (original magnification × 400); E: Canalicular adenoma accompanying low-grade intraepithelial neoplastic change and more deposited schistosomal ova in rectum (original magnification × 40); F: Same view as A, at a different magnification (original magnification × 100); G: Rectal adenocarcinoma and deposited schistosomal ova in rectum (original magnification × 40); H: Same view as A, at a different magnification (original magnification × 100).