髓系肉瘤的CT和MRI影像学分析

Analysis of CT and MRI manifestations of myeloid sarcoma

目的:分析髓系肉瘤(MS)的影像学表现,提高对该病的认识。方法:回顾性分析经病理证实的18例髓系肉瘤患者的临床和影像学资料,总结其影像学特征。患者年龄15~67岁,中位年龄40岁,14例为白血病性MS,4例为孤立性MS(非白血病性MS)。结果:单发14例,多发4例。16例(88.9%)边界不规则;14例(77.8%)密度/信号不均匀,平扫CT(43.35±7.95)HU;18例均未见包膜和内部钙化;7例(38.8%)伴有坏死,1例有囊变,1例有出血;增强扫描11例均表现为不同程度的强化。MRI显示病灶在T 1WI上呈等~低信号,T 2WI上呈等~高信号,DWI上为高或稍高信号。白血病性MS影像学诊断符合率为85.7%,孤立性MS为25%。结论:髓系肉瘤的影像学表现缺乏特异性,白血病性髓系肉瘤结合病史易于诊断,孤立性MS诊断困难,确诊需依靠免疫组化检查。

Objective:The aim of this study was to analyze the imaging features of myeloid sarcoma(MS)and to improve the understanding of the disease.Methods:The clinical and imaging data of 18 patients(15~47 years old,median 40 years old)with myeloid sarcoma confirmed by pathology were analyzed retrospectively.14 cases were leukemic MS,4 cases were isolated MS(non leukemia MS).Results:14 cases were single and 4 cases were of multiple lesions.16 cases(88.9%)had irregular boundary,14(77.8%)cases had uneven density/signal.The mean CT value of the lesions on plain scan was(43.35±7.95)HU.No capsule or internal calcification was found in all 18 cases.Tumor necrosis was found in 7 cases(38.8%);1 case with cystic degeneration and 1 with hemorrhage.All of the 11 cases showed different degree of enhancement on contrast scan.The tumors showed iso-or hypo-intensity on T 1WI,iso-or slight hyper-intensity on T 2WI and high or slightly high signal on DWI.The accuracy of imaging diagnosis of leukemic MS was 85.7%and that of solitary MS was 25%.Conclusion:Myeloid sarcoma is a rare disease.The imaging manifestations are lack of specificity.Leukemic MS is quite easy to diagnose with knowledge of patient's medical history.Isolated MS is difficult to be diagnosed,which depends on immunohistochemistry.