Case Report
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 21, 2017; 23(31): 5817-5822
Published online Aug 21, 2017. doi: 10.3748/wjg.v23.i31.5817
Rarity among benign gastric tumors: Plexiform fibromyxoma - Report of two cases
Kinga Szurian, Holger Till, Eva Amerstorfer, Nicole Hinteregger, Hans-Jörg Mischinger, Bernadette Liegl-Atzwanger, Iva Brcic
Kinga Szurian, Bernadette Liegl-Atzwanger, Iva Brcic, Institute of Pathology, Medical University of Graz, 8036 Graz, Austria
Holger Till, Eva Amerstorfer, Department of Paediatric and Adolescent Surgery, Medical University of Graz, 8036 Graz, Austria
Nicole Hinteregger, Department of Radiology, Division of Neuroradiology, Vascular and Interventional Radiology, Medical University of Graz, 8036 Graz, Austria
Hans-Jörg Mischinger, Department of Surgery, Medical University of Graz, 8036 Graz, Austria
Author contributions: Szurian K and Brcic I designed the report; Till H, Amerstorfer E, Hinteregger N and Mischinger HJ collected the patients’ clinical data; Szurian K, Till H, Amerstorfer E, Liegl-Atzwanger B and Brcic I analyzed the data and wrote the paper; Hinteregger N and Mischinger HJ revised the paper; All authors approved the final manuscript.
Institutional review board statement: Since medical treatment was conducted according to highest clinical standards, the present report of two cases is not of experimental character and does not require an ethical committee statement.
Informed consent statement: Informed consent was obtained from both patients.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
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: Iva Brcic, MD, Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, 8036 Graz, Austria. iva.brcic@medunigraz.at
Telephone: +43-316-38578031 Fax: +43-316-384329
Received: February 10, 2017
Peer-review started: February 12, 2017
First decision: March 16, 2017
Revised: April 3, 2017
Accepted: May 4, 2017
Article in press: May 4, 2017
Published online: August 21, 2017
Processing time: 190 Days and 6 Hours
Abstract

Plexiform fibromyxoma is a very rare mesenchymal tumor of the stomach, found almost exclusively in the antrum/pylorus region. The most common presenting symptoms are anemia, hematemesis, nausea and unintentional weight loss, without sex or age predilection. We describe here two cases of plexiform fibromyxoma, involving a 16-year-old female and a 34-year-old male. Both patients underwent complete resection (R0) by distal gastrectomy and retrocolic gastrojejunostomy (according to Billroth 2); for both, the postoperative course was uneventful. Histology showed multiple intramural and subserosal nodules with characteristic plexiform growth, featuring bland spindle cells situated in an abundant myxoid stroma with low mitotic activity. Immunohistochemistry showed α-smooth muscle actin-positive spindle cells, focal positivity for CD10, and negative staining for KIT, DOG1, CD34, S100, β-catenin, STAT-6 and anaplastic lymphoma kinase. One of the cases showed focal positivity for h-caldesmon and desmin. Upon follow-up, no sign of disease was found. In the differential diagnosis of plexiform fibromyxoma, it is important to exclude the more common gastrointestinal stromal tumors as they have greater potential for aggressive behavior. Other lesions, like neuronal and vascular tumors, inflammatory fibroid polyps, abdominal desmoid-type fibromatosis, solitary fibrous tumors and smooth muscle tumors, must also be excluded.

Keywords: Plexiform fibromyxoma; Plexiform angiomyxoid myofibroblastic tumor; Gastrointestinal stromal tumor; Stomach; Benign gastric tumor

Core tip: Plexiform fibromyxoma is a very rare benign mesenchymal tumor of the stomach. Here, we describe two cases of plexiform fibromyxoma, resolved with complete resection. The macroscopic, microscopic, immunohistochemical and molecular findings are reviewed. In the differential diagnosis of plexiform fibromyxoma, it is important to exclude the more common gastrointestinal stromal tumors as they have potentially more aggressive behavior.