Case Report
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 28, 2015; 21(4): 1329-1333
Published online Jan 28, 2015. doi: 10.3748/wjg.v21.i4.1329
Mixed adenoneuroendocrine carcinoma of gastrointestinal tract: Report of two cases
Simona Gurzu, Zoltan Kadar, Tivadar Bara, Tivadar Jr. Bara, Adrian Tamasi, Leonard Azamfirei, Ioan Jung
Simona Gurzu, Zoltan Kadar, Adrian Tamasi, Ioan Jung, Department of Pathology, University of Medicine and Pharmacy, 540139 Tirgu Mures, Romania
Tivadar Bara, Tivadar Jr. Bara, Department of Surgery, University of Medicine and Pharmacy, 540139 Tirgu Mures, Romania
Leonard Azamfirei, Intensive Care Unit, University of Medicine and Pharmacy, 540139 Tirgu Mures, Romania
Author contributions: Gurzu S wrote the manuscript and carried out the study design; Kadar Z carried out the oncological management and interpretation of oncological data; Bara T carried out the surgical interventions and interpretation of the data from literature; Bara TJ participated at surgical interventions and interpretation of clinical data; Tamasi A participated at histological and immunohistochemical interpretation of data; Azamfirei L carried out the draft of the manuscript and revision of technical data; Jung I carried out the histological examination and immunoassays coordinated the study design and the draft of the manuscript.
Supported by Romanian government, the research project frame POSDRU/159/1.5/S/136893, and University of Medicine and Pharmacy of Tirgu-Mures, Romania, the team research project POS-UMFTGM-CC-13-01-V01, No. 15/16189/2013.
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: Simona Gurzu, MD, PhD, Associate Professor, Department of Pathology, University of Medicine and Pharmacy, 38 Ghe Marinescu Str., 540139 Tirgu Mures, Romania. simonagurzu@yahoo.com
Telephone: +40-74-5673550 Fax: +40-74-5673550
Received: June 3, 2014
Peer-review started: June 6, 2014
First decision: July 21, 2014
Revised: August 3, 2014
Accepted: September 29, 2014
Article in press: September 30, 2014
Published online: January 28, 2015
Abstract

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumor of the gastrointestinal tract that consists of a dual adenocarcinomatous and neuroendocrine differentiation, each component representing at least 30% of the tumor. To date, only seven cases have been reported in the cecum, and less than 40 in the stomach. Our first case was diagnosed in a 74-years-old female as a polypoid lesion of the cecum with direct invasion in the transverse colon, without lymph node metastases. The second case was diagnosed in the stomach of a 46-years-old male as a polypoid tumor of the antral region that invaded the pancreas and presented metastases in 22 regional lymph nodes. The metastatic tissue was represented by the glandular component. In both cases, the tumor consisted of a moderately-differentiated tubular adenocarcinoma (with mucinous component in Case 1) intermingled with neuroendocrine carcinoma. Ki67 index was lower than 20% in Case 1, respectively higher than 20% in Case 2. The neuroendocrine component was marked by synaptophysin and neuron specific enolase, being negative for Keratins 7/20. The neuroendocrine component represented 60% in Case 1, and 40% in Case 2, respectively. The glandular components were marked by carcinoembryonic antigen, maspin and keratin 20/7 (Case 1/2). Both cases were proved to be microsatellite stable. Independently by the localization and tumor stage, MANECs appear to be highly malignant tumors, with high risk for distant metastases. The aggressiveness seems to depend on the endocrine component, independent of its proportion. The neuroendocrine component could be a dedifferentiated adenocarcinoma with a neuroendocrine phenotype.

Keywords: Mixed adenoneuroendocrine carcinoma, Composite tumor, Mixed tumor, Colorectal, Stomach, Cecum, Maspin, Carcinoembryonic antigen, Keratin 7, Keratin 20

Core tip: The aim of this paper was to report the clinicopathological data of two cases of mixed adenoneuroendocrine carcinomas (MANECs), one in the cecum and one in the stomach. MANEC is a rare tumor of the gastrointestinal tract that consists of a dual adenocarcinomatous and neuroendocrine differentiation. To date, only seven cases have been reported in the cecum, and less than 40 in the stomach. The characteristics of these cases, in correlation with data from literature, proved that MANEC is a highly malignant tumor, its aggressiveness being related to the endocrine component, independent of its proportion.