Supplementary Material for: Efficacy of S-1 treatment in Recurrent and Metastatic Orbital Sebaceous Gland Carcinoma After Orbital Exenteration

Introduction: Herein, we report a case of recurrent and metastatic sebaceous gland carcinoma (SGC) following orbital exenteration, which was managed with S-1 administration.
Case Presentation: The patient was a 78-year-old man. At the initial examination, the extension of SGC into the right orbit was noted, for which radiotherapy, instead of orbital exenteration, was administered as per patient preference. However, after 2 years, the tumor enlarged, necessitating right orbital exenteration. Six months after the procedure, recurrence with orbital apex involvement, invasion into the supraorbital wall, and metastasis to the right cervical lymph nodes were observed. Therefore, resection of the supraorbital wall and temporalis muscle skin valve and dissection of the right cervical lymph nodes were performed. Seven months later, positron emission tomography/computed tomography revealed intraorbital recurrence, right submandibular gland metastasis, and lung metastasis. Accordingly, S-1 treatment was initiated, following which the intraorbital lesions and metastases disappeared; the patient remained in remission 1 year later.
Conclusion: Our findings suggest that S-1 treatment may be effective in the management of refractory SGC.