Abstract
AB004. A case report of mediastinal germ cell tumor with vasculogenic mesenchymal tumor components sharing a PTEN mutation with acute megakaryoblastic leukemia
Yu Naito1,2, Natsuko Sakurai1, Hideo Arai1, Shin-ichiro Horiguchi1, Toru Motoi1, Daichi Sadato3, Yuka Harada3, Noriko Doki4, Tsunekazu Hishima1
1Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan;
2Department of Pathology, Graduate School of Medicine, Nagoya University, Nagoya, Japan;
3Department of Clinical Research, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan;
4Department of Hematology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
Correspondence to: Yu Naito, MD. Department of Pathology, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan. Email: ingyu7110ngy@gmail.com.
Background: A vasculogenic mesenchymal tumor (VMT) is a newly proposed entity of neoplasm that can develop in a mediastinal germ cell tumor (GCT) after chemotherapy. Levy defined VMT as an expansion of mesenchymal cells forming atypical vasculature, which did not meet the diagnostic criteria for angiosarcoma in several points, exceeding one low-power (4× objective) microscopic field. Additionally, Levy reported that the presence of VMT was associated with a high risk of developing hematological malignancies during the clinical course. Only a few reports have demonstrated genetic association among GCT, VMT, and associated hematological malignancies.
Case Description: A 30-year-old man with no personal or family history of cancer was referred to Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital due to a mediastinal mass. The tumor was clinically diagnosed as a mediastinal GCT with a nonseminomatous component. After chemotherapy, the tumor was resected in February of the following year. During postoperative chemotherapy, only 2 months after the resection, he developed acute megakaryoblastic leukemia (AMKL) in the same year, which was clinically thought to be a hematological malignancy associated with the mediastinal GCT. After undergoing bone marrow transplantation, he passed away. Macroscopically, the mediastinal tumor was 16.5 cm in size. Histologically, the tumor was a GCT with extensive vasculogenic stroma. The stromal cells with mild to moderate nuclear atypia exhibited various vessel-like structures. Immunohistochemical analysis revealed that the cells forming the vascular-like structures were CD34(+) and ERG(+), leading to a diagnosis of GCT with VMT component. No leukemia cells were found in the GCT. Immunohistochemically, the GCT cells and VMT cells commonly exhibited loss of PTEN expression and overexpression of p53. Next-generation sequencing (NGS) revealed the same PTEN gene mutation shared in GCT and AMKL.
Conclusions: Here, we showed a rare case of GCT with a VMT component and associated AMKL. Genetic testing revealed a PTEN mutation common to the GCT and the AMKL, possibly originating from the common tumoral clone. The mediastinal GCT should be diagnosed with attention to the presence of a VMT component, considering its potential risk for hematological malignancies.
Keywords: Vasculogenic mesenchymal tumor (VMT); leukemia; 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-ab004/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-ab004
Cite this abstract as: Naito Y, Sakurai N, Arai H, Horiguchi SI, Motoi T, Sadato D, Harada Y, Doki N, Hishima T. AB004. A case report of mediastinal germ cell tumor with vasculogenic mesenchymal tumor components sharing a PTEN mutation with acute megakaryoblastic leukemia. Mediastinum 2024;8:AB004.
