Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Aug 16, 2021; 9(23): 6872-6878
Published online Aug 16, 2021. doi: 10.12998/wjcc.v9.i23.6872
Trismus originating from rare fungal myositis in pterygoid muscles: A case report
Ling Bi, Dong Wei, Bo Wang, Jian-Feng He, Hui-Yong Zhu, Hui-Ming Wang
Ling Bi, Dong Wei, Jian-Feng He, Hui-Yong Zhu, Hui-Ming Wang, Department of Stomatology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
Bo Wang, Department of Pathology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
Hui-Ming Wang, Department of Oral and Maxillofacial Surgery, The Affiliated Hospital of Stomatology, School of Stomatology, Zhejiang University School of Medicine, and Key Laboratory of Oral Biomedical Research of Zhejiang Province, Hangzhou 310006, Zhejiang Province, China
Author contributions: Bi L analyzed the patient’s data and wrote the manuscript; Wei D performed the treatment plan and the operation; Wang B performed the pathological analyses and interpretation; He JF collected the data and performed the follow-up; Zhu HY was responsible for the revision of the manuscript; Wang HM reviewed the literature and approved the final version of the manuscript as the supervisor.
Supported by Natural Science Foundation of Zhejiang Province, China, No. LQ19H160019; Zhejiang Provincial Basic Public Welfare Research Project, China, No. LGF19H140006; Zhejiang TCM Science and Technology Plan, China, No. 2018ZA071, and No. 2019ZA069; and Medical Scientific Research Foundation of Zhejiang Province, China, No. 2019KY379.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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/
Corresponding author: Hui-Ming Wang, MD, PhD, Chief Doctor, Professor, Department of Stomatology, First Affiliated Hospital, School of Medicine, Zhejiang University, No. 79 Qingchun Road, Hangzhou 310003, Zhejiang Province, China. whmwhm@zju.edu.cn
Received: April 15, 2021
Peer-review started: April 15, 2021
First decision: May 10, 2021
Revised: May 20, 2021
Accepted: May 26, 2021
Article in press: May 26, 2021
Published online: August 16, 2021
Processing time: 112 Days and 1.8 Hours
Abstract
BACKGROUND

Trismus is a common problem with various causes. Any abnormal conditions of relevant anatomic structures that disturb the free movement of the jaw might provoke trismus. Trismus has a detrimental effect on the quality of life. The outcome of this abnormality is critically dependent on timely diagnosis and treatment, and it is difficult to identify the true origin in some cases. We present a rare case of trismus due to fungal myositis in the pterygoid muscle, excluding any other possible pathogenesis.

CASE SUMMARY

The patient presented with a 2-mo history of restricted mouth opening. Computed tomography showed obvious enlargement of the left pterygoid muscles. Furthermore, the patient had trismus without obvious predisposing causes. The primary diagnosis was pterygoid myosarcoma. Consequently, lesionectomy of the left pterygoid muscle was performed. Intraoperative frozen biopsy implied the possibility of an uncommon infection. Postoperative pathologic examination confirmed myositis and necrosis in the pterygoid muscle. Fungi were detected in both muscle tissue and surrounding necrotic tissue. The patient recovered well with antifungal therapy and mouth opening exercises. The rarity of fungal myositis may be responsible for the misdiagnosis. Although the origin of pathogenic fungi is still unknown, we believe that both hematogenous spread and local invasion could be the most likely sources. To the best of our knowledge, this is the first case in the literature that reported fungal myositis in pterygoid muscles as the only reason that results in trismus.

CONCLUSION

Surgeons should remain vigilant to the possibility of trismus originating from fungal myositis.

Keywords: Trismus; Fungal myositis; Infection; Immunodeficiency; Pterygoid muscle; Case report

Core Tip: Trismus has a detrimental effect on the quality of life. Early diagnosis and treatment have the potential to minimize the consequences of this condition. However, it is not always easy to identify the true origin in some cases. We report the first case in the literature that fungal myositis in pterygoid muscles is the only reason for trismus. We initially misdiagnosed this case of fungal origin because of its rarity. Surgeons should consider the possibility of fungal myositis in trismus diagnosis.