Case Report
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 28, 2016; 22(36): 8234-8241
Published online Sep 28, 2016. doi: 10.3748/wjg.v22.i36.8234
Diagnosis of colonic amebiasis and coexisting signet-ring cell carcinoma in intestinal biopsy
Alexandra Grosse
Alexandra Grosse, Institute of Clinical Pathology, University Hospital Zurich, 8091 Zurich, Switzerland
Author contributions: Grosse A designed the report, collected the patient’s clinical and histopathological data, analyzed and interpreted the data and wrote the paper.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board (Kantonale Ethikkommission Zürich).
Informed consent statement: Written informed consent was obtained from the patient for publication of this Case Report and any accompanying images.
Conflict-of-interest statement: The author has no conflicts of interests to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Alexandra Grosse, MD, Institute of Clinical Pathology, University Hospital Zurich, Schmelzbergstraße 12, 8091 Zurich, Switzerland. alexandra.grosse@usz.ch
Telephone: +41-44-2552637 Fax: +41-44-2554440
Received: May 2, 2016
Peer-review started: May 2, 2016
First decision: June 20, 201
Revised: July 7, 2016
Accepted: July 31, 2016
Article in press: August 1, 2016
Published online: September 28, 2016
Processing time: 146 Days and 10.2 Hours
Abstract

Amebiasis is uncommon in developed countries. Several case reports in the literature emphasize that both the presenting symptoms and the radiological findings of colonic amebiasis closely resemble more common conditions, such as idiopathic inflammatory bowel disease and gastro-intestinal malignancy. We describe a unique case of colonic amebiasis (amebomas) coexisting with signet-ring cell carcinoma of the ileocecal valve, the cecum and the appendix. Endoscopically, the ulcerated tumor was indistinguishable from the ulcerations and pseudotumors (amebomas) detected in the ascending colon. Histological examination of biopsy specimens revealed the pathognomonic features of protozoa with ingested erythrocytes in combination with signet-ring cell infiltration. The author concludes that amebiasis may not only mimic carcinoma but, rarely, may coexist with carcinoma in the same patient. Clinicians and pathologists should be aware of this possibility in order not to delay diagnosis and treatment of malignant disease.

Keywords: Colonic amebiasis; Histopathology; Parasitic disease; Colorectal carcinoma; Colonoscopy

Core tip: This case report presents the unique case of a patient in whom colonic amebiasis (amebomas) and signet-ring cell carcinoma of the ileocecal valve, the cecum and the appendix were diagnosed in intestinal biopsy specimens. In the setting of amebiasis, malignancy may easily be overlooked. Therefore, clinicians and pathologists should be aware that colonic amebiasis and colorectal carcinoma may coexist in the same patient.