Genetic Testing and Immunotherapy for Intracranial Inflammatory Myofibroblastic Tumor: A Case Report

Xiangji Meng,1,* Lei Zhang,2,* Qi Wang,3 Jimin Chen,2 Chunmei Zhang,2 Rongjie Tao,4 Yong Wang5,6 1Department of Neurosurgery, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, People’s Republic of China; 2Department of Translational Medicine, Genecast Biotechnology Co., Ltd, Wuxi, Jiangsu, 214104, People’s Republic of China; 3Department of Paediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, 250021, People’s Republic of China; 4Department of Medical Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, People’s Republic of China; 5Shandong Cancer Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250117, People’s Republic of China; 6Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, Peoples’ Republic of China*These authors contributed equally to this workCorrespondence: Yong Wang, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, No. 440, Jiyan Road, Jinan, Shandong, 250117, People’s Republic of China, Email doctorwy@163.com Rongjie Tao, Department of Medical Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, People’s Republic of China, Email rongjietao@163.comAbstract: Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that can develop in numerous organs, most commonly in the lungs and rarely in the brain. Here, we reported a 55-year-old patient with nasopharyngeal IMT and the recurrence in the skull base, slope and pterygoid sinus who underwent cranial base and slope tumor resection. Postoperative magnetic resonance imaging (MRI) and multiplex immunohistochemistry (mIHC) showed tumor recurrence and metastasis to the intracalvarium. While genetic testing revealed no significant related gene mutations, tertiary mutations in NSD1 and SOX9 genes were identified in the tumor tissues. The patient achieved partial remission after receiving 7 cycles of immunotherapy (toripalimab 240 mg for 1 cycle followed by 6 cycles of sintilimab 200 mg), and MRI examination indicated an almost complete remission of intracranial IMT after 16 cycles of immunotherapy. In summary, the novel class of immune-targeted agents may be effective in clinical management of rare intracranial IMT.Keywords: inflammatory myofibroblastic tumor, sintilimab, multiplex immunohistochemistry, magnetic resonance imaging, immunotherapy