Vaughn John L, Freitag C Eric, Hemminger Jessica A, Jones Jeffrey A
Department of Internal Medicine, The Ohio State University, Columbus, OH, USA.
Department of Pathology, The Ohio State University, Columbus, OH, USA.
J Med Case Rep. 2017 Apr 5;11(1):92. doi: 10.1186/s13256-017-1253-z.
Histiocytic sarcoma is a rare histiocytic neoplasm of unknown etiology that constitutes less than 1% of hematologic malignancies. A few cases of histiocytic sarcoma harboring the BRAF mutation have been reported, but this finding has not been confirmed in all studies.
We report the case of a 63-year-old white woman with a history of splenic marginal zone lymphoma who presented with 2 weeks of right-sided neck swelling. Positron emission tomography revealed an intensely hypermetabolic and destructive soft tissue mass in her right skull base. A bone marrow biopsy was performed, which revealed an infiltrate of malignant cells characterized as large pleomorphic cells with frequent folded/irregular nuclei, variably prominent nucleoli, fine chromatin, and abundant amounts of eosinophilic cytoplasm. The malignant cells were positive for CD163, CD68 (granular), lysozyme (granular), CD4, and CD45 (partial). Based on the biopsy findings, she was diagnosed as having histiocytic sarcoma. The malignant cells tested positive for the BRAF protein using immunohistochemistry. Before treatment of her histiocytic sarcoma could be initiated, she developed disseminated intravascular coagulation and acute hypoxemic respiratory failure secondary to non-cardiogenic pulmonary edema. She decided to pursue comfort care and died in our hospital 2 weeks following admission.
Our case illustrates the aggressive nature of histiocytic sarcoma, and provides rare evidence that histiocytic sarcoma associated with indolent lymphomas may harbor the BRAF mutation. Further research is needed to clarify the role of targeted therapies such as vemurafenib in the treatment of patients with this disorder.
组织细胞肉瘤是一种病因不明的罕见组织细胞肿瘤，占血液系统恶性肿瘤的比例不到1%。已有少数关于携带BRAF突变的组织细胞肉瘤病例的报道，但并非所有研究都证实了这一发现。
我们报告了一名63岁白人女性的病例，她有脾边缘区淋巴瘤病史，出现右侧颈部肿胀2周。正电子发射断层扫描显示其右颅底有一个代谢极度活跃且具有破坏性的软组织肿块。进行了骨髓活检，结果显示有恶性细胞浸润，这些细胞特征为大的多形性细胞，核频繁折叠/不规则，核仁大小不一，染色质细腻，有大量嗜酸性细胞质。恶性细胞CD163、CD68（颗粒状）、溶菌酶（颗粒状）、CD4和CD45（部分）呈阳性。根据活检结果，她被诊断为组织细胞肉瘤。使用免疫组织化学检测，恶性细胞BRAF蛋白呈阳性。在开始治疗她的组织细胞肉瘤之前，她出现了弥散性血管内凝血和继发于非心源性肺水肿的急性低氧性呼吸衰竭。她决定接受姑息治疗，入院2周后在我院死亡。
我们的病例说明了组织细胞肉瘤的侵袭性，并提供了罕见的证据，即与惰性淋巴瘤相关的组织细胞肉瘤可能携带BRAF突变。需要进一步研究以阐明维莫非尼等靶向治疗在该疾病患者治疗中的作用。
