摘要目的 探讨低度恶性纤维黏液样肉瘤(LGFMS)的临床病理学特征、免疫学表型和鉴别诊断.方法 分析9例LGFMS的临床表现、影像学、组织学和免疫学表型特点.免疫组织化学染色采用EnVision法,所用一抗为波形蛋白、平滑肌肌动抗原(α-SMA)、肌特异性抗原(MSA)、高分子钙调蛋白(h-caldesmon)、结蛋白、CD34、CD99、S-100蛋白、CD57(Leu 7)、bcl-2、细胞角蛋白(AE1/AE3)、上皮细胞膜抗原(EMA)和KP-1(CD68).结果 男性5例,女性4例,年龄范围为11-65岁(平均31.4岁).临床上表现为四肢、躯干和颈部缓慢增大的无痛性肿块,2例有近期内肿块生长迅速的病史,3例因肿块局部切除后复发就诊.超声检查显示肿瘤内信号高低不一.CT平扫显示为低至等密度的结节状肿块,增强CT提示肿瘤内密度不均.MRI-T1加权显示为低密度信号,MRI-T2加权显示高密度和低密度区域交错性分布.大体上肿块呈结节状,直径为3～16 cm(平均7.7 cm),切面呈灰白色,纤维至纤维黏液样.组织学上,肿瘤由交替性分布的胶原性区域和黏液样区域组成,两种区域之间可见有移行.3例肿瘤内另见有巨菊形团形成.在巨菊形团与纤维黏液性成分之间也有过渡现象.巨菊形团的中央由嗜伊红色的胶原纤维组成,常呈离心状排列.高倍镜下,瘤细胞呈短梭形或卵圆形,核深染,异型性不明显或仅有轻度的异型性,核分裂象罕见.瘤细胞多呈交织状或旋涡状排列.肿瘤内血管不丰富,也不见凝固性坏死.免疫组织化学标记显示瘤细胞主要表达波形蛋白,部分表达CD34,不表达α-SMA、结蛋白、h-caldesmon、CD99、S-100蛋白和bcl-2等标记.结论 LGFMS是一种好发于青年人的低度恶性纤维母细胞性肉瘤,熟悉其临床病理学特征有助于避免将其误诊为良性肿瘤.临床上对LGFMS宜采取局部扩大切除术,以降低局部复发的危险性.

abstractsObjective To study the clinicopathological features, immnophenotype and differential diagnosis of low-grade fibromyxoid sarcoma (LGFMS). Methods The clinical, radiological and pathological features of 9 cases of LGFMS were reviewed. Results The patients consisted of six males and three females with ages ranging from 11 to 65 years ( mean 31.4 years). Clinically, most cases presented as slowly growing painless masses located in the extremities, trunk and neck. Two cases had a history of a rapid recent enlargement. Three cases presented with recurrent diseases after incomplete resection. Ultrasound showed heterogeneous signal. Plecontrast CT and T1-weighted MRI showed a nodular mass of low to isodensity, while contrast-enhanced CT and T2-weighted MRI demonstrated contrasting zonal areas of hypo/ hyperintensity. The tumors measured 3 to 16 cm (mean 7. 7 cm), with a fibrous to myxoid appearance on cut surface. Histologically, they were composed of alternating collagenous and myxoid areas. A transition between the two areas could be identified. Giant rosette-like structures were observed in 3 cases. The center of the giant rosettes was composed of eosinophilic collagen, which showed centrifugal in arrangement. There was also gradual transition between the giant rosettes and the fibromyxoid component. On high magnification,the tumor was composed of ovoid to spindle-shaped cells with hyperchromatic nuclei. Nuclear atypia was inconspicuous. The tumor cells were arranged mostly in interlacing fascicles or whorls. Vessels were not prominent and necrosis was absent. Immunohistochemically, the tumor cells showed unique staining for vimentin,consistent with a fibroblastic differentiation.Conclusions LGFMS is a distinctive low grade fibroblastic sarcoma of young adults.Recognizing the characteristics of the rare entity may help to avoid misdiagnosis.Wide local excision is recommended to avoid local recurrences.