Case Report
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Feb 26, 2020; 8(4): 782-789
Published online Feb 26, 2020. doi: 10.12998/wjcc.v8.i4.782
Extrapleural solitary fibrous tumor of the thyroid gland: A case report and review of literature
Yong Joon Suh, Jung Ho Park, Jae Hyeon Jeon, Sanchir-Erdene Bilegsaikhan
Yong Joon Suh, Jung Ho Park, Department of Breast and Endocrine Surgery, Hallym University Sacred Heart Hospital, Gyeonggi-do 14068, South Korea
Jae Hyeon Jeon, Sanchir-Erdene Bilegsaikhan, Department of Biomedical Science, Hallym University, Chuncheon 24252, South Korea
Author contributions: Suh YJ designed the study; Bilegsaikhan SE collected the data; Suh YJ and Bilegsaikhan SE drafted the manuscript; Suh YJ revised the manuscript critically. All authors read and approved the final manuscript.
Supported by the National Research Foundation of Korea grant funded by the Korea government, No. 2019R1G1A1004679.
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: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Yong Joon Suh, MD, PhD, Department of Breast and Endocrine Surgery, Hallym University Sacred Heart Hospital, No. 22 Gwanpyeong-ro 170 beon-gil, Dongan-gu, Anyang-si, Gyeonggi-do 14068, South Korea. nicizm@gmail.com
Received: December 9, 2019
Peer-review started: December 9, 2019
First decision: December 30, 2019
Revised: January 13, 2020
Accepted: January 19, 2020
Article in press: January 19, 2020
Published online: February 26, 2020
Abstract
BACKGROUND

Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm that arises from the pleura. A few SFTs have also been described in extrapleural sites. However, SFT of the thyroid gland is rare. Here, we report a case of extrapleural SFT on the thyroid gland, in addition to a literature review.

CASE SUMMARY

A 59-year-old man visited our hospital in July 2017 complaining of a large mass in his neck. His thyroid function test results, including antibody levels, were within the normal limits. Ultrasonography showed a 4.7 cm × 4.0 cm × 3.2 cm solitary mass of intermediate suspicion in the left thyroid lobe. A fine-needle aspiration biopsy was subsequently performed. The pathologist reported a benign follicular lesion. However, the size of this nodule increased to 5.5 cm × 5.0 cm × 3.4 cm by April 2018. After a multidisciplinary discussion, a left lobectomy was performed in May 2018. The specimen showed a well-demarcated, partly encapsulated, soft nodule of whitish and tan/brown color on the cut surface. Light microscopy revealed high cellularity with moderate cytologic atypia. The mitotic count was 5/10 high-power fields. There was no tumor necrosis or lymphovascular invasion. The tumor was CD34-positive and signal transducer and activator of transcription 6-positive. Neither thyroid transcription factor-1 nor cytokeratin expression was detected. The Ki-67 showed intermediate proliferative activity. The final diagnosis was extrapleural SFT of the thyroid gland with a clear resection margin. The patient was discharged without complication three days after the surgery.

CONCLUSION

In the literature, extrapleural SFT of the thyroid gland has been reported to behave indolently with the capacity for recurrence and rare metastasis, although surgical resection is the treatment of choice. Understanding this disease entity is important for accurate diagnosis and proper management.

Keywords: Solitary fibrous tumor, Mesenchymal neoplasm, Thyroid gland, Surgery, Case report, Review

Core tip: This report presents laboratory, radiologic, and pathologic findings about the extrapleural solitary fibrous tumor of the thyroid gland. Not much is known about its behavior or prognosis because of the rarity of these tumors. Therefore, a comprehensive literature review is also performed, which covers all the cases published in English.