Primary tumors of the spinal cord are rare, accounting for 3–6% of tumors in the central nervous system, particularly in children. KIAA1549-BRAF fusion is more common in pilocytic astrocytoma (PA) and IDH1 R132H mutation is rare in infratentorial tumors. Here, we report a 10-year-old male patient who presented with weakness in lower limbs that progressed to difficulty walking. Magnetic resonance imaging (MRI) revealed an intramedullary solid-cystic lesion from the medulla oblongata to the thoracic spin 4 level, with the expansion of the spinal cord. The lesion exhibited patchy enhancement at C4-T1, indicating a tentative diagnosis of astrocytoma. The patient underwent resection of the lesion in the spinal canal from the cervical 6 level to the thoracic 2 level. Histopathology confirmed diagnosis of astrocytoma, WHO grade 2. Genetic analysis showed both IDH1 R132H mutation and KIAA1549-BRAF fusion. Therefore, our integrated diagnosis was astrocytoma, IDH mutation, WHO grade 2. Its molecular analyses include IDH1 R132H mutation and KIAA1549-BRAF fusion. After the operation, the patient did not receive chemo- or radiotherapy, and underwent an aggressive rehabilitation regiment. Follow up 10 months later, symptoms improved. To our best knowledge, this is the first case of concomitant IDH mutation and BRAF fusion in pediatric spinal cord astrocytoma.

脊髓原发肿瘤很少见，占中枢神经系统肿瘤的 3-6%，尤其是儿童。KIAA1549-BRAF 融合在毛细胞星形细胞瘤 (PA) 中更常见，IDH1 R132H 突变在幕下肿瘤中很少见。在这里，我们报告了一名 10 岁男性患者，他出现下肢无力并进展为行走困难。磁共振成像 (MRI) 显示从延髓到胸椎旋转 4 水平的髓内实性囊性病变，伴有脊髓扩张。病变在 C4-T1 处表现出斑片状增强，表明初步诊断为星形细胞瘤。患者接受了从颈椎 6 节到胸椎 2 节的椎管内病灶切除术。组织病理学证实星形细胞瘤的诊断，WHO 2 级。遗传分析显示 IDH1 R132H 突变和 KIAA1549-BRAF 融合。因此，我们综合诊断为星形细胞瘤，IDH突变，WHO 2级。其分子分析包括IDH1 R132H突变和KIAA1549-BRAF融合。手术后，患者没有接受化疗或放疗，而是接受了积极的康复治疗。10个月后随访，症状有所改善。据我们所知，这是小儿脊髓星形细胞瘤中第一例伴随 IDH 突变和 BRAF 融合的病例。并接受了积极的康复团。10个月后随访，症状有所改善。据我们所知，这是小儿脊髓星形细胞瘤中第一例伴随 IDH 突变和 BRAF 融合的病例。并接受了积极的康复团。10个月后随访，症状有所改善。据我们所知，这是小儿脊髓星形细胞瘤中第一例伴随 IDH 突变和 BRAF 融合的病例。