Interesting Image

¹⁸F-FDG PET/CT Showing Rare Mediastinal Growing Teratoma Syndrome Following Chemotherapy

10.4274/mirt.galenos.2021.54775

• Mihoko Sasahara
• Takashi Abe
• Yoichi Otomi
• Yumi Abe
• Hiroaki Toba
• Takayoshi Shinya
• Hideki Otsuka
• Masafumi Harada

Received Date: 27.05.2021 Accepted Date: 05.09.2021 Mol Imaging Radionucl Ther 2022;31(3):239-241 PMID: 36268930

• Abstract
• Full Text
• Video - Image
• References
• 1
• 491

Growing teratoma syndrome (GTS) is a condition in which poorly differentiated cells in a mixed-germ cell tumor (GCT) regress after chemotherapy, and the number of well-differentiated components increases. A 60-year-old man had an 8.0 cm mediastinal tumor with strong ¹⁸F-fluorodeoxyglucose (FDG) uptake [maximum standardized uptake value (SUV_max): 9.2], which was diagnosed as a GCT. After chemotherapy, serum alpha fetoprotein, beta-human chorionic gonadotropin, and tumor ¹⁸F-FDG uptake decreased (SUV_max: 3.9), but the tumor volume increased. The tumor was completely resected, and pathology confirmed the diagnosis of GTS. ¹⁸F-FDG positron emission tomography after chemotherapy reflects the proliferation of highly differentiated tumor components with poor ¹⁸F-FDG uptake.

Keywords: Growing teratoma syndrome, 18F-FDG PET, mediastinum, germ cell tumor

Ethics

Informed Consent: Written informed consent of the patient was obtained.

Peer-review: Externally peer-reviewed.

Authorship Contributions

Surgical and Medical Practices: Y.O., Y.A., H.T., T.S., H.O., Concept: T.A., T.S., Design: M.S., T.A., Data Collection or Processing: M.S., Y.O., M.H., Analysis or Interpretation: M.S., M.H., Literature Search: M.S., T.A., Writing: M.S., T.A., Y.O.

Conflict of Interest: No conflict of interest is declared by the authors.

Financial Disclosure: The authors declare that this study received no financial support.

Images

1. Dulmet EM, Macchiarini P, Suc B, Verley JM. Germ cell tumors of the mediastinum. A 30-year experience. Cancer 1993;72:1894-1901.
2. Logothetis CJ, Samuels ML, Trindade A, Johnson DE. The growing teratoma syndrome. Cancer 1982;50:1629-1635.
3. DiSaia PJ, Saltz A, Kagan AR, Morrow CP. Chemotherapeutic retroconversion of immature teratoma of the ovary. Obstet Gynecol 1977;49:346-350.
4. Saso S, Galazis N, Iacovou C, Kappatou K, Tzafetas M, Jones B, Yazbek J, Lathouras K, Anderson J, Jiao LR, Smith RJ. Managing growing teratoma syndrome: new insights and clinical applications. Future Sci OA 2019;5:FSO419.
5. Omachi N, Kawaguchi T, Shimizu S, Okuma T, Kitaichi M, Atagi S, Yoon HE, Matsumura A. Life-threatening and rapidly growing teratoma in the anterior mediastinum. Intern Med 2015;54:2487-2489.
6. Kikawa S, Todo Y, Minobe S, Yamashiro K, Kato H, Sakuragi N. Growing teratoma syndrome of the ovary: a case report with FDG-PET findings. J Obstet Gynaecol Res 2011;37:926-932.
7. Hariprasad R, Kumar L, Janga D, Kumar S, Vijayaraghavan M. Growing teratoma syndrome of ovary. Int J Clin Oncol 2008;13:83-87.