Imataki Osamu, Uemura Makiko, Fujita Haruyuki, Kadowaki Norimitsu
Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Kagawa University, Miki, Kagawa 761-0793, Japan.
Mol Clin Oncol. 2022 Jul 15;17(3):136. doi: 10.3892/mco.2022.2569. eCollection 2022 Sep.
Histiocytic sarcoma (HS) is a rare hematological malignancy, which exhibits morphological and immunophenotypic features of histiocytes. A standard therapy for HS has not yet been established due to its rareness; therefore, disease control is not always possible. A multimodal treatment strategy has been suggested for HS. The present study reported on a case of a 43-year-old female patient who complained of left femoral pain, which was caused by left femoral bone mass. A biopsy of their left femoral bone tumor revealed that the patient had HS. Their sarcoma was localized in the femoral bone and was not considered to be curable, due to local infiltration of the bone tumor beyond the periosteum. The patient then underwent two types of HS-specific chemotherapy; however, both regimens were ineffective. As a result, they underwent radiation therapy at the sites of progressive disease. Because the HS cells of the patient expressed PD-L1, they were treated with nivolumab (240 mg/body, biweekly) for residual diseases in the right occipital bone, multiple lung nodules, intrapelvic right lymph node and primary site. Nivolumab treatment resulted in a complete response at all sites, with the exception of the primary site, which was confirmed by F-fluorodeoxyglucose-positron emission tomography/computed tomography. The patient received additional nivolumab treatment as consolidation therapy for 1 year. In addition, residual disease of the femoral head was completely resected. The surgically resected refractory tumor revealed the tumor cells no longer pathologically expressed PD-L1 . In conclusion, for refractory and recurrent HS in which surgical resection is not appropriate, treatment with immune-checkpoint inhibitors, such as nivolumab, may be considered an optional but promising immunotherapy if the tumor histologically expresses PD-L1. The present study detected one of the refractory mechanisms of ICI treatment.
组织细胞肉瘤（HS）是一种罕见的血液系统恶性肿瘤，具有组织细胞的形态学和免疫表型特征。由于其罕见性，HS的标准治疗方法尚未确立；因此，疾病控制并非总是可行的。有人提出了一种针对HS的多模式治疗策略。本研究报告了一例43岁女性患者，该患者主诉左股骨疼痛，由左股骨骨肿块引起。对其左股骨骨肿瘤进行活检后发现该患者患有HS。其肉瘤局限于股骨，由于骨肿瘤局部浸润超过骨膜，被认为无法治愈。该患者随后接受了两种针对HS的化疗；然而，两种方案均无效。结果，他们在疾病进展部位接受了放射治疗。由于该患者的HS细胞表达程序性死亡受体配体1（PD-L1），因此针对其右枕骨、多个肺结节、盆腔右侧淋巴结和原发部位的残留病灶，使用纳武单抗（240mg/体，每两周一次）进行治疗。除原发部位外，纳武单抗治疗在所有部位均产生了完全缓解，这通过F-氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描得到证实。该患者接受了额外的纳武单抗治疗作为巩固治疗，为期1年。此外，股骨头的残留病灶被完全切除。手术切除的难治性肿瘤显示肿瘤细胞在病理上不再表达PD-L1。总之，对于不适合手术切除的难治性和复发性HS，如果肿瘤在组织学上表达PD-L1，使用免疫检查点抑制剂（如纳武单抗）进行治疗可能被认为是一种可选但有前景的免疫疗法。本研究发现了免疫检查点抑制剂治疗的一种难治机制。
