Case Report
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 14, 2018; 24(2): 303-309
Published online Jan 14, 2018. doi: 10.3748/wjg.v24.i2.303
Successful treatment of a giant ossified benign mesenteric schwannoma
Ying-Sheng Wu, Shao-Yan Xu, Jing Jin, Ke Sun, Zhen-Hua Hu, Wei-Lin Wang
Ying-Sheng Wu, Shao-Yan Xu, Jing Jin, Zhen-Hua Hu, Wei-Lin Wang, Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
Ying-Sheng Wu, Shao-Yan Xu, Jing Jin, Zhen-Hua Hu, Wei-Lin Wang, Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Hangzhou 310003, Zhejiang Province, China
Ying-Sheng Wu, Shao-Yan Xu, Jing Jin, Zhen-Hua Hu, Wei-Lin Wang, Key Laboratory of Organ Transplantation, Hangzhou 310003, Zhejiang Province, China
Ying-Sheng Wu, Shao-Yan Xu, Jing Jin, Zhen-Hua Hu, Wei-Lin Wang, Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Hangzhou 310003, Zhejiang Province, China
Ying-Sheng Wu, Shao-Yan Xu, Jing Jin, Zhen-Hua Hu, Wei-Lin Wang, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
Ke Sun, Department of Pathology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
Author contributions: Wu YS and Xu SY contributed equally to this work and should be considered co-first authors; Wu YS, Xu SY and Jing Jin collected case data, prepared the photos and wrote the manuscript; Sun K proofread the pathologic materials; Hu ZH and Wang WL proofread and revised the manuscript; all of the authors approved the final version to be published.
Supported by the National Natural Science Foundation of China, No. 81572307.
Informed consent statement: Informed consent was obtained from the patient.
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this report.
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: Wei-Lin Wang, PhD, MD, Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, 79# Qingchun road, Hangzhou 310003, Zhejiang Province, China. wam@zju.edu.cn
Telephone: +86-571-87236466 Fax: +86-571-87236466
Received: August 30, 2017
Peer-review started: August 31, 2017
First decision: September 20, 2017
Revised: October 3, 2017
Accepted: October 26, 2017
Article in press: October 26, 2017
Published online: January 14, 2018
Processing time: 136 Days and 13.4 Hours
ARTICLE HIGHLIGHTS
Case characteristics

A 58-year-old woman visited our department due to a lesion detected incidentally in her abdominal cavity during a routine health examination in the local hospital.

Clinical diagnosis

A lesion, palpable in the her upper left abdomen, was sized 12 cm × 6 cm, and she felt slight tenderness.

Differential diagnosis

Gastrointestinal stromal tumour, intra-abdominal teratoma, sarcoma and neurogenic tumour.

Laboratory diagnosis

Blood test findings, including tumour markers, were unremarkable.

Imaging diagnosis

Ultrasound revealed a solid lesion in the upper left abdomen, with clear margin, and also showed some cystic and strong echo areas in the lesion. Color doppler flow imagings (CDFIs) showed blood signals in the lesion. In a native computed tomography (CT) scan, the lesion in the upper left abdomen appeared well-defined and was 9.6 cm in diameter, while regions of high density were visible, compatible with calcification and/or ossification. Contrast-enhanced CT study revealed a lesion with slight and inhomogeneous enhancement. On T1-weighted images, the upper left abdominal lesion appeared hypointense, while appeared inhomogeneous and hyperintense on T2-weighted images (Figure 2). According to these imaging results, the abdominal lesion was primarily considered to be a teratoma.

Pathological diagnosis

Macroscopically, the mass was 10.0 cm × 9.0 cm × 9.0 cm in size and yellowish-white in colour. Microscopically, in the mesenteric tumour, both hypercellular and hypocellular areas were visible. The tumour mainly consisted of spindle-shaped cells with a palisading arrangement; atypical cells or signs of malignancy were not observed. Some areas of the tumour were ossified, and a true metaplastic bone formation could be seen, with the presence of bone lamellae and osteoblasts. Immunohistochemical investigation of the tumour showed a strong positivity for S-100 protein , while SMA, CD34, CD117 and DOG-1 were negative. The cell proliferation index, measured with Ki67 staining, was less than 3%. Finally, a giant benign ossified mesenteric schwannoma was diagnosed.

Treatment

The authors completely resected the mass located in the mesentery by laparotomy.

Related reports

Schwannomas in the bowel mesentery are extremely rare. To our knowledge, only 9 cases of schwannomas located in the bowel mesentery have been reported. In addition, mesenteric schwannoma with ossified degeneration has not been reported thus far.

Experiences and lessons

In the present study, the authors present the first giant ossified benign mesenteric schwannoma. It was difficult to obtain an accurate diagnosis of the mesenteric schwannoma preoperatively, because of the lack of specific symptoms, radiological characteristics and tumour markers.