Amebic Colitis Can Mimic Tuberculosis and Inflammatory Bowel Disease on Endoscopy and Biopsy

Abstract

Biopsies of 11 patients with histopathologically diagnosed amebic colitis was evaluated; endoscopically, they were suspected to have tuberculosis or inflammatory bowel disease. Amebiasis was suggested in the differential diagnosis in only 3 cases. Three patients had purely rectal or sigmoid involvement, whereas the others had ileocecal, cecal, ascending, or transverse colon disease. The biopsies showed cryptitis and depletion of mucin but no crypt branching. Crypt abscesses were seen in one biopsy. Trophozoites of Entamoeba histolytica were seen in the exudate in all cases. The trophozoites were round to oval, approximately 25 to 40 microm in diameter and had a single, round nucleus and periodic acid-Schiff-positive cytoplasm. Phagocytosed erythrocytes were present in the trophozoites. Some features of ulcerative colitis and infectious colitis, such as cryptitis and crypt abscesses, are also seen in amebic colitis. Amebic colitis must be included in the differential diagnosis of all patients with suspected inflammatory bowel disease and tuberculosis.

Investigation of Entamoeba histolytica and Mycobacterium spp. in biopsy specimens of patients with inflammatory bowel disease in Turkey

“…In a study, 11 patients were described most of which were initially suspected to be tuberculosis or IBD based on the clinical and endoscopic findings. Eight of these patients were diagnosed as amoebic colitis only on histopathological evaluation of the colonic endoscopic biopsy (Pai, 2008). On the other hand, a negative biopsy does not always rule out amebiasis and repeated biopsies may be needed for the diagnosis (Mendonca et al, 1977).…”

“…Because of the considerable overlapping features and the difficulty of the differential diagnosis, amebiasis is sometimes falsely diagnosed as inflammatory bowel disease exacerbation (Pai, 2008).…”

Combined Endoscopy, Aspiration, and Biopsy Analysis for Identifying Infectious Colitis in Patients With Ileocecal Ulcers

“…[1][2][3]5,10,11 Thus, we first assessed patients for typical endoscopic findings and then clarified an effective method of sample collection for diagnosing infectious colitis.…”

“…[1][2][3][4] Of the many infectious agents, Yersinia spp., Salmonella spp., Campylobacter spp., enterohemorrhagic Escherichia coli, Mycobacterium tuberculosis, nontuberculous mycobacteria (NTM), cytomegalovirus (CMV), and intestinal amebiasis have been associated with ileocecal involvement. 1,2,[5][6][7][8][9][10][11][12][13] Besides infection, inflammatory bowel disease (IBD), systemic disorders including intestinal Behçet's disease and ischemia, as well as nonsteroidal anti-inflammatory drugs (NSAIDs), may also lead to ileocecal inflammation. [2][3][4] Diagnosing the cause of infectious colitis involving the ileocecal area is of paramount importance because the definite diagnosis of IBD requires infection to be ruled out because misdiagnosis or treatment for IBD with immunosuppressants or corticosteroids may result in serious consequences or undesirable outcome.…”

“…However, differential diagnosis of infectious colitis and other inflammatory diseases can be difficult in clinical practice because GI symptoms may reflect a number of diseases. [1][2][3]5,11 Diagnosis of infectious colitis requires identification of the offending pathogen and usually relies on stool culture. However, successful identification by using samples from patients with diarrhea is extremely low (2.0%-6.1%).…”