Abstract
A 54-year-old man with diarrhea and hematochezia for 2 months was referred to our department. A total colonoscopy revealed amoebic colitis caused by Entamoeba histolytica. Concurrently, a submucosal tumor-like yellowish hemispheric polypoid lesion was incidentally detected in the rectum. We speculated that the lesion was a NET, which could be cured by endoscopic treatment. However, histopathological assessment of a biopsy specimen unexpectedly revealed a well- or moderately differentiated adenocarcinoma. After treatment of the amoebic colitis, endoscopic ultrasound revealed a low, hetero-echoic, 6-mm-diameter lesion mainly in the submucosal layer. We performed surgical resection because the invasion was estimated to be to the deeper submucosal layer. Histopathological assessment of the surgically resected specimen revealed a focal lesion of a well-differentiated adenocarcinoma in the granulation tissue of the submucosal layer. In cases accompanied by amoebic colitis, a tumor’s initial gross type might change. Diagnostic endoscopic resection could be acceptable in such cases.
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References
Shreya C, Zachary ZA, Nikhil A. Kumta: diagnosis and management of rectal neuroendocrine tumors. Clin Endosc. 2017;50(6):530–6.
Niimi K, Goto O, Fujishiro M, et al. Endoscopic mucosal resection with a ligation device or endoscopic submucosal dissection for rectal carcinoid tumors: an analysis of 24 consecutive cases. Dig Endosc. 2012;6:443–7.
Sekiguchi M, Sekine S, Sakamoto T, et al. Excellent prognosis following endoscopic resection of patients with rectal neuroendocrine tumors despite the frequent presence of lymphovascular invasion. J Gastroenterol. 2015;50(12):1184–9.
Abe T, Kawai N, Yasumaru M, et al. Ameboma mimicking colon cancer. Gastrointest Endosc. 2009;69(3 Pt 2):757–8.
Kantor M, Abrantes A, Estevez A, et al. Entamoeba histolytica. Updates in clinical manifestation, pathogenesis, and vaccine development. Can J Gastroenterol Hepatol. 2018. https://doi.org/10.1155/2018/4601420.
Espinosa-Cantellano M, Martinez-Palomo A. Pathogenesis of intestinal amebiasis: from molecules to disease. Clin Microbiol. 2000;13:318–31.
McCarthy AJ, Chetty R. Gut-associated lymphoid tissue or so-called “dome” carcinoma of the colon: review. World J Gastrointest Oncol. 2019;11(1):59–70.
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Shun Ito, Satoshi Ono, Akihiro Kobayashi, Kyohei Maejima, Shosuke Hosaka, Kiyotaka Umeki, Shin-ichiro Sato, Satoshi Wakasugi, and Kenji Ogata declare that they have no conflict of interest.
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Ito, S., Ono, S., Kobayashi, A. et al. A case of a rectal adenocarcinoma mimicking a neuroendocrine tumor in the background mucosa of amoebic colitis. Clin J Gastroenterol 13, 552–554 (2020). https://doi.org/10.1007/s12328-019-01088-1
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DOI: https://doi.org/10.1007/s12328-019-01088-1