Kanno H, Kanetsuna Y, Shinonaga M. Anaplastic myxopapillary ependymoma: A case report and review of literature. World J Clin Oncol 2021; 12(11): 1072-1082 [PMID: 34909401 DOI: 10.5306/wjco.v12.i11.1072]
Corresponding Author of This Article
Hiroshi Kanno, MD, PhD, Professor, Surgical Oncologist, Department of Neurosurgery, International University of Health and Welfare Atami Hospital, 13-1 East Coast, Atami 413-0012, Shizuoka, Japan. hiroshikannomd@nifty.com
Research Domain of This Article
Oncology
Article-Type of This Article
Case Report
Open-Access Policy of This Article
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/
Hiroshi Kanno, Masamichi Shinonaga, Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Shizuoka, Japan
Yukiko Kanetsuna, Department of Pathology, International University of Health and Welfare Atami Hospital, Atami 413-0012, Shizuoka, Japan
Author contributions: Kanetsuna Y performed the histological evaluation; Kanno H drafted the manuscript, the table and figures; Shinonaga M evaluated the clinical data and reviewed the manuscript.
Informed consent statement: Written informed consent was obtained from the patient before surgical treatment. In addition, all procedures performed in this study were in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Conflict-of-interest statement: The authors declare no conflict 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: Hiroshi Kanno, MD, PhD, Professor, Surgical Oncologist, Department of Neurosurgery, International University of Health and Welfare Atami Hospital, 13-1 East Coast, Atami 413-0012, Shizuoka, Japan. hiroshikannomd@nifty.com
Received: February 23, 2021 Peer-review started: February 23, 2021 First decision: May 4, 2021 Revised: May 5, 2021 Accepted: October 11, 2021 Article in press: October 11, 2021 Published online: November 24, 2021 Processing time: 269 Days and 0.6 Hours
Abstract
BACKGROUND
Myxopapillary ependymoma (MPE) is a pathological grade I tumor that arises in the filum terminale. MPE with anaplastic features is extremely rare, and only 5 cases have shown malignancy at the time of recurrence.
CASE SUMMARY
The patient (a 46-year-old woman) had undergone a MPE operation 30 years ago. After subtotal resection of the tumor located in L4-S1, it had a solid component that extended to the adjacent subcutaneous region. Histologically, the tumor consisted of a typical MPE with anaplastic features. The anaplastic areas of the tumor showed hypercellularity, a rapid mitotic rate, vascular proliferation, and connective tissue proliferation. Pleomorphic cells and atypical mitotic figures were occasionally observed. The MIB-1 index in this area was 12.3%. The immunohistochemical study showed immunoreactivity for vimentin, glial fibrillary acidic protein and S100. The morphological pattern and immunohistochemical profile were consistent with anaplastic MPE. The patient tolerated surgery well without new neurological deficits. She underwent local irradiation for the residual tumor and rehabilitation.
CONCLUSION
Although extremely rare, anaplastic MPE occurs in both pediatric and adult patients, similar to other ependymomas. At a minimum, close monitoring is recommended, given concerns about aggressive biological potential. In the future, further study is needed to determine the WHO classification criteria and genetic indicators of tumor progression. The possibility of malignant transformation of MPE should be taken into account, and patients with MPE should be treated with care and follow-up.
Core Tip: Myxopapillary ependymoma (MPE) is a pathological grade I tumor that develops in the filum terminale. MPEs with anaplastic features are extremely rare; only 5 cases have shown malignancy when they relapsed. Here we report a case of MPE with anaplastic features in local late recurrence in a 46-year-old woman and review anaplastic MPE in the published literature. MPEs have the potential for malignant transformation after a long period of time despite being a pathological grade I tumor. Therefore, the possibility of malignant transformation of the MPE should be considered, and patients with MPE should be treated carefully and monitored over a long period of time.
