黏液型滑膜肉瘤2例并文献复习

Myxoid synovial sarcoma: a report of 2 cases and literature review

目的探讨黏液型滑膜肉瘤(myxoid synovial sarcoma,MSS)的临床病理学特征、诊断及鉴别诊断。方法对2例MSS进行组织形态学观察、免疫组化染色、分子病理学检测并复习相关文献。结果例1男性,例2女性。年龄分别为71岁及15岁。例1肿物位于左下腹,例2肿物位于左侧额颞叶。镜检:例1低倍镜下肿瘤呈结节样,结节内肿瘤由细胞疏松区与致密区组成。疏松区细胞呈漩涡状、束状、片状排列,间质见大量黏液样基质,细胞异型性明显。致密区细胞丰富,瘤细胞呈束状、鱼骨样排列。例2肿瘤由细胞疏松区及致密区组成,两者间相互移行。疏松区细胞呈疏松网状、片状排列,间质见大量黏液样基质。部分区域见少量上皮样细胞,呈小簇状分布。致密区细胞丰富,呈束状、片状排列。未侵犯脑组织。免疫表型:例1,BCL-2、vimentin阳性,α-SMA和EMA部分细胞阳性,CD34、CD57、S-100、CD117、PLAP均阴性。例2,BCL-2阳性,Myo D1胞质阳性,GFAP、Olig-2、EMA、Syn、CD99、Cg A、S-100、Myogenin、STAT6、CD34、desmin、α-SMA均阴性。分子病理学检测:2例均检测到SYT-SSX融合基因。结论 MSS是一种罕见的软组织恶性肿瘤,确诊主要依靠分子病理学检测,临床与病理均需与黏液型纤维肉瘤、孤立性纤维性肿瘤等鉴别。治疗以手术切除联合放疗为主,预后不良。

Purpose To investigate the clinicopathological features, diagnosis and differential diagnosis of myxoid synovial sarcoma （MSS）. Methods Clinicopathological changes and immunophenotype were retrospectively evaluated in two MSS cases collected from Fujian Provincial Hospital, combined with genetic mutation analysis. The relevant literatures were reviewed to explore its clinical and pathological features of this tumor. Results The two cases, one man and one woman, aged 71 and 15 years, respectively. Tumor was located in the left down abdomen in case 1, and left frontal temporal lobe in case 2. Histopathologically, at low magnification in case 1, the tumor was nodular, which was made up of areas of hypereellularity and hypocellularity. In some areas of hypocellularity, the tumor cells were arranged in faseicular, story-form, sheet arrangements with mucoid degeneration. In hypercellularity area, the tumor cells were arranged in fascicular, fish bone-liked arrangements. At low magnification in ease 2, the tumor was nodular, which was made up of areas of hypercellularity and hypocellularity. In hypocellularity area, the tumor cells were arranged in net-like, sheet arrangements, and fascicular, sheet arrangements in case 2. In some area, the tumor cells were epithelioid with cluster distribution, without infringing brain tissue. Immunohistochemically, the tumor cells were diffusely positive for BCL-2, vimentin, and α-SMA and EMA were partially positive, while CD34, CD57, S-100, CD117, PLAP were negative. However, in case 2, only BCL-2 was positive, and MyoD1, GFAP, Olig-2, EMA, Syn, CD99, CgA, S-100, Myogenin, STAT6, CD34, desmin and α- SMA were negative. Molecular detection SYT-SSX fusion gene was detected in both cases. Conclusion MSS is a rare malignancy of soft tissue. The diagnosis of MSS depends on molecular pathology. The clinical and pathological findings are different from mucinous fibrosarcoma and solitary fibrous tumor. The treatment is surgical resection, combined with radiotherapy, with poor prognosis.