Abstract：
BACKGROUND: Patients with histiocytic sarcoma occurring in the central nervous system (CNS) are rare and have a very poor prognosis. The increased use of molecular diagnostic approaches in solid tumors has brought more opportunities for the diagnosis and treatment of central nervous system histiocytic sarcoma (CNSHS).
METHODS: A 9-year-old girl was admitted to the hospital with pain in her head and neck, as well as vomiting. Imaging scans showed a prominent abnormality in the anterior falciform region, and histopathology revealed the presence of CD68 (+) and CD163 (+) cells, leading to a preliminary diagnosis of primary intracerebral CNSHS. Molecular profiling tests identified a new variant of ARHGAP45::BRAF fusion in this case, which has not been reported in any other tumor. The patient underwent surgical removal of the tumor and will require long-term monitoring.
CONCLUSIONS: The presence of the BRAF point mutation, predominantly BRAF p.V600E, has been documented in prior literature of CNSHS. This is the first case of pediatric histiocytic sarcoma in the anterior falciform region who has a unique ARHGAP45::BRAF fusion. The findings of our study indicate that a broader range of molecular assays should be employed in the diagnosis of CNSHS and opens up new possibilities for the treatment of the patient.
METHODS: A 9-year-old girl was admitted to the hospital with pain in her head and neck, as well as vomiting. Imaging scans showed a prominent abnormality in the anterior falciform region, and histopathology revealed the presence of CD68 (+) and CD163 (+) cells, leading to a preliminary diagnosis of primary intracerebral CNSHS. Molecular profiling tests identified a new variant of ARHGAP45::BRAF fusion in this case, which has not been reported in any other tumor. The patient underwent surgical removal of the tumor and will require long-term monitoring.
CONCLUSIONS: The presence of the BRAF point mutation, predominantly BRAF p.V600E, has been documented in prior literature of CNSHS. This is the first case of pediatric histiocytic sarcoma in the anterior falciform region who has a unique ARHGAP45::BRAF fusion. The findings of our study indicate that a broader range of molecular assays should be employed in the diagnosis of CNSHS and opens up new possibilities for the treatment of the patient.
摘要：
背景：发生在中枢神经系统（CNS）的组织细胞肉瘤患者很少见，预后极差。实体瘤中分子诊断方法的增加为中枢神经系统组织细胞肉瘤（CNSHS）的诊断和治疗带来了更多的机会。
方法：一名9岁女孩因头颈部疼痛入院，还有呕吐。影像学扫描显示前镰状区有明显异常，和组织病理学显示CD68（+）和CD163（+）细胞的存在，导致原发性脑内CNSHS的初步诊断。分子谱分析测试确定了ARHGAP45的一种新变体::BRAF融合在这种情况下，在任何其他肿瘤中均未见报道。患者接受了手术切除肿瘤，需要长期监测。
结论：BRAF点突变的存在，主要是BRAFp.V600E，已在CNSHS的先前文献中记录。这是前镰状区小儿组织细胞肉瘤的第一例，具有独特的ARHGAP45::BRAF融合。我们的研究结果表明，在CNSHS的诊断中应采用更广泛的分子检测方法，并为患者的治疗开辟了新的可能性。
方法：一名9岁女孩因头颈部疼痛入院，还有呕吐。影像学扫描显示前镰状区有明显异常，和组织病理学显示CD68（+）和CD163（+）细胞的存在，导致原发性脑内CNSHS的初步诊断。分子谱分析测试确定了ARHGAP45的一种新变体::BRAF融合在这种情况下，在任何其他肿瘤中均未见报道。患者接受了手术切除肿瘤，需要长期监测。
结论：BRAF点突变的存在，主要是BRAFp.V600E，已在CNSHS的先前文献中记录。这是前镰状区小儿组织细胞肉瘤的第一例，具有独特的ARHGAP45::BRAF融合。我们的研究结果表明，在CNSHS的诊断中应采用更广泛的分子检测方法，并为患者的治疗开辟了新的可能性。
