Abstract
A 36-year-old woman underwent proton beam therapy for encapsulated type B1 thymoma for curative intent at 66 GyE. Radiographically partial response was achieved. Although the tumor size had been stable since that time, she developed systemic myasthenia gravis 10 years after the proton therapy. Extended thymectomy was performed. There were no adhesions between the tumor and the pericardium, and there were no adhesions also between the tumor and the sternum, probably due to the favor of Bragg peak effect. Extensive hyalinization with small foci of viable tumor cells showing degenerated type A-like morphology was observed in the resected tumor. Whether the viable cells represented recurrence with degenerative changes or de novo tumor formation was unable to be determined, and whether the viable cells were responsible for the onset of myasthenia gravis remained unclear.
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References
Kondo K. Therapy for thymic epithelial tumors. Gen Thorac Cardiovasc Surg. 2014;62:468–74.
Sakamoto M, Murakawa T, Konoeda C, Inoue Y, Kitano K, Sano A, et al. Survival after extended thymectomy for thymoma. Eur J Cardiothorac Surg. 2012;41:623–7.
Chang JY, Zhang X, Wang X, Kang Y, Riley B, Bilton S, et al. Significant reduction of normal tissue dose by proton radiotherapy compared with three-dimensional conformal or intensity-modulated radiation therapy in Stage I or Stage III non-small-cell lung cancer. Int J Radiat Oncol Biol Phys. 2006;65:1087–96.
Onuki T, Ishikawa S, Yamamoto T, Ito H, Sakai M, Onizuka M, et al. Pathologic radioresponse of preoperatively irradiated invasive thymomas. J Thorac Oncol. 2008;3:270–6.
Nakagawa K, Asamura H, Sakurai H, Watanabe S, Tsuta K. Does the mode of surgical resection affect the prognosis/recurrence in patients with thymoma? J Surg Oncol. 2014;109:179–83.
Tseng YC, Hsieh CC, Huang HY, Huang CS, Hsu WH, Huang BS, et al. Is thymectomy necessary in nonmyasthenic patients with early thymoma? J Thorac Oncol. 2013;8:952–8.
Nakajima J, Murakawa T, Fukami T, Sano A, Takamoto S, Ohtsu H. Postthymectomy myasthenia gravis: relationship with thymoma and antiacetylcholine receptor antibody. Ann Thorac Surg. 2008;86:941–5.
Okumura M, Fujii Y, Shiono H, Inoue M, Minami M, Utsumi T, et al. Immunological function of thymoma and pathogenesis of paraneoplastic myasthenia gravis. Gen Thorac Cardiovasc Surg. 2008;56:143–50.
Björk-Eriksson T, Bjelkengren G, Glimelius B. The potentials of proton beam radiation therapy in malignant lymphoma, thymoma and sarcoma. Acta Oncol. 2005;44:913–7.
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Karasaki, T., Murakawa, T., Nagayama, K. et al. New onset of myasthenia gravis 10 years after proton beam therapy for thymoma. Gen Thorac Cardiovasc Surg 64, 290–293 (2016). https://doi.org/10.1007/s11748-014-0484-9
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DOI: https://doi.org/10.1007/s11748-014-0484-9