Abstract
AB025. Primary posterior mediastinal benign leiomyoma arising from accessory hemiazygos vein: a case report
Naoto Kitahara1, Yoshihisa Kadota1, Seiji Taniguchi1, Hiroto Ishida1, Hirokazu Watari1, Kayo Ueda2, Hideo Mori2
1Department of Thoracic Surgery, Osaka Habikino Medical Center, Habikino, Osaka, Japan;
2Department of Diagnostic Pathology, Osaka Habikino Medical Center, Habikino, Osaka, Japan
Correspondence to: Naoto Kitahara, MD. Department of Thoracic Surgery, Osaka Habikino Medical Center, 3-7-1, Habikino, Habikino, Osaka 583-0872, Japan. Email: kitapara92@gmail.com.
Background: Leiomyomas in posterior mediastinal tumors are most commonly of esophageal origin and rarely arise from blood vessels. We report a case of a posterior mediastinal leiomyoma arising from the accessory hemiazygos vein that was resected thoracoscopically, which is extremely rare.
Case Description: A 71-year-old male was referred to our hospital because of a posterior mediastinal tumor that was discovered by chance during a preoperative computed tomography (CT) scan for an inguinal hernia. He had hypertension and hyperuricemia since he was 50 years old. At 59 years old, he had a motorcycle accident, and his left rib fracture, clavicle fracture, and scapula fracture were treated conservatively and he recovered well. Enhanced CT showed a 3 cm tumor with smooth margins between the left 10th and 11th ribs, adjacent to the accessory hemiazygos vein. CT value showed a contrast effect, plain CT value was 30 Hounsfield unit (HU), while enhanced one was 61 HU. The patient underwent 3-port thoracoscopic surgery with CO2 insufflation. The tumor was not able to be partially dissected from the accessory hemiazygos vein, and bleeding occurred, so the vessel was clipped in the longitudinal direction near the tumor and separated. The small residual tumor was attached to the vessel wall and a combined resection was performed. The patient was discharged without postoperative complications. Microscopical examination of the tumor showed proliferation of spindle-shaped tumor cells as well as muscle fibers. There was no evidence of necrosis or fission. The leiomyoma was adherent to a portion of the outer membrane of the vein, and the tumor was contiguous with the myofibers within the vessel wall. Immunohistochemistry for α smooth muscle actin (SMA) and desmin shows positivity in tumor cells, while the one for S-100, AE1/AE3, D2-40, CD34, PGP9.5 is negative. Ki-67 shows 8%. Estrogen receptor (ER), caldesmon, and calponin staining is attempted, but it is difficult to differentiate tumor from vascular smooth muscle tissue. Based on the above pathological results and intraoperative findings, we diagnose the primary posterior mediastinal tumor originating from the accessory hemiazygos vein rather than extravascular invasion of the tumor. One year after surgery, there was no apparent recurrence.
Conclusions: This is an extremely rare case that we resected the posterior mediastinal tumor thoracoscopically and diagnosed as the leiomyoma of accessory hemiazygos vein.
Keywords: Leiomyoma; accessory hemiazygos vein; surgery; case report
Acknowledgments
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://med.amegroups.com/article/view/10.21037/med-24-ab025/coif). The authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report. A copy of the written consent is available for review by the editorial office of this journal.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
doi: 10.21037/med-24-ab025
Cite this abstract as: Kitahara N, Kadota Y, Taniguchi S, Ishida H, Watari H, Ueda K, Mori H. AB025. Primary posterior mediastinal benign leiomyoma arising from accessory hemiazygos vein: a case report. Mediastinum 2024;8:AB025.
