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©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
Dedifferentiated chondrosarcoma of the middle finger arising from a solitary enchondroma: A case report
Hirotaka Yonezawa, Norio Yamamoto, Katsuhiro Hayashi, Akihiko Takeuchi, Shinji Miwa, Kentaro Igarashi, Sei Morinaga, Yohei Asano, Shiro Saito, Yasunori Tome, Hiroko Ikeda, Takayuki Nojima, Hiroyuki Tsuchiya
Hirotaka Yonezawa, Norio Yamamoto, Katsuhiro Hayashi, Akihiko Takeuchi, Shinji Miwa, Kentaro Igarashi, Sei Morinaga, Yohei Asano, Shiro Saito, Takayuki Nojima, Hiroyuki Tsuchiya, Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Ishikawa, Japan
Yasunori Tome, Department of Orthopedic Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara 903-0215, Okinawa, Japan
Hiroko Ikeda, Takayuki Nojima, Department of Diagnostic Pathology, Kanazawa University Hospital, Kanazawa 920-8641, Ishikawa, Japan
Author contributions: Tsuchiya H, Tome Y and Yonezawa H served as the patient’s surgeons, reviewed the literature and contributed to manuscript drafting; Ikeda H and Nojima T reviewed the pathological findings and contributed to manuscript drafting; Yamamoto N, Hayashi K, Takeuchi A and Miwa S analyzed and interpreted the imaging findings; Igarashi K, Morinaga S, Asano Y and Saito S were responsible for the revision of the manuscript for important intellectual content; all authors issued final approval for the version to be submitted.
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 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:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Norio Yamamoto, MD, PhD, Professor, Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Ishikawa, Japan. norinori@med.kanazawa-u.ac.jp
Received: November 15, 2021
Peer-review started: November 15, 2021
First decision: January 11, 2022
Revised: January 19, 2022
Accepted: February 20, 2022
Article in press: February 20, 2022
Published online: April 6, 2022
BACKGROUND
Dedifferentiated chondrosarcoma (DDCS) accounts for 10% of all chondrosarcomas and has the poorest outcome, with a 5-year survival rate of 7%-25%. DDCS commonly occurs in the femur and pelvis, whereas DDCS of the finger is extremely rare. Furthermore, the histological findings of preexisting solitary enchondroma samples are important and valuable for diagnosing malignant transformations.
CASE SUMMARY
We report our experience with DDCS in the proximal phalanx of the left middle finger of an 87-year-old woman. She had undergone surgery for enchondroma, with curettage and artificial bone grafting, 11 years ago, in the same location. Several years after the primary surgery, the left middle finger gradually started to enlarge, and the growth speed increased in the past year. Plain radiographs showed an expansive osteolytic lesion with calcifications and residual grafting material. Owing to the suspicion of malignancy, we performed ray amputation. Histological findings revealed an abrupt transition between the low-grade chondrosarcoma and dedifferentiated sarcoma components. The dedifferentiated components showed the features of a high-grade undifferentiated pleomorphic sarcoma. The patient was diagnosed with DDCS arising from a preexisting enchondroma. She had no local recurrence or distant metastasis and died of pneumonia 6 years and 10 months after the second surgery.
CONCLUSION
The histological findings of a precursor lesion showed a typical enchondroma, suggesting that DDCS can arise from enchondroma.
Core Tip: Dedifferentiated chondrosarcoma (DDCS) is a very rare primary malignant bone tumor. Furthermore, malignant transformation of a single enchondroma of the hand bone into DDCS is considered extremely rare, with no detail of precursor pathological findings being reported previously. There have been no reports showing preexisting enchondromas prior to wide resection. Our report evaluated the histological findings of a precursor lesion, and the specimen showed a typical benign enchondroma, suggesting that DDCS can arise from enchondroma.
