背景:低级别纤维黏液样肉瘤(LGFM)是一种罕见的纤维肉瘤,主要发生在年轻人身上,主要见于躯干和四肢。肿瘤通常是由t(7;16)(q32-34;p11)染色体易位引起的FUS-CREB3L2融合,很少有FUS-CREB3L1和EWSR1-CREB3L1融合。MUC4漫溢性强阳性可作为LGFM的特异性指标。LGFM与硬化性上皮样纤维肉瘤(SEF)相似,可能具有相同的起源。
方法:我们报告一例胸壁LGFM。一位59岁的女性。2016年CT显示左侧胸膜浓密结节影和局灶性增厚,病人接受了手术,病理报告为低至中度恶性纤维肉瘤(纤维粘液样型)。2021年的CT复检显示,左胸壁的肿瘤比以前明显增大。病理检查显示该疾病由交替的胶原样和粘液样区域组成。在高倍显微镜下,肿瘤细胞形状一致,主轴或短主轴,肿瘤细胞排列成束。在当地,肿瘤细胞的密度显著增加,与胶原纤维混合,出现小病灶SEF。免疫组化结果显示SMA,Desmin,CD34、STAT6、S100、SOX10、HMB45和MelanA均为阴性,EMA呈弱阳性,MUC4呈弥漫性和强阳性,Ki67指数较低(3%)。
结论:测序结果表明,MET,EGFR,KMT2B和RET基因在LGFM中突变,且KMT2B基因有促癌作用,但是LGFM没有文献报道,这可能对LGFM的诊断和治疗具有一定的意义。
BACKGROUND: Low-grade Fibromyxoid Sarcoma(LGFM)is a rare fibrosarcoma, which mainly occurs in young people and is mostly seen in the trunk and limbs. The tumor is usually
FUS-CREB3L2 fusion caused by t(7;16)(q32-34;p11)chromosome translocation, and rarely
FUS-CREB3L1 and EWSR1-CREB3L1 fusion. MUC4 diffuse strong positive can be used as a specific index of LGFM. LGFM is similar to Sclerosing Epithelioid Fibrosarcoma(SEF) and may have the same origin.
METHODS: We report a case of LGFM in the chest wall. A female who is 59 years old. In 2016, CT showed dense nodule shadow and focal thickening of the left pleura, the patient underwent surgery, Pathological report that low to moderate malignant fibrosarcoma(fibromyxoid type). The CT re-examination in 2021 showed that the tumors on the left chest wall were significantly larger than before. Pathological examination showed the disease is composed of alternating collagen like and mucinous areas. Under high-power microscope, the tumor cells are consistent in shape, spindle or short spindle, and the tumor cells are arranged in bundles. In local areas, the density of tumor cells is significantly increased, mixed with collagen fibers, and small focal SEF appear. The result of immunohistochemistry showed that SMA, Desmin, CD34, STAT6, S100, SOX10, HMB45 and Melan A were negative, EMA was weakly positive, MUC4 was diffuse and strongly positive, and Ki67 index was low (3%).
CONCLUSIONS: Sequencing results showed that MET, EGFR, KMT2B and RET gene were mutated in LGFM, and KMT2B gene had cancer promoting effect, but there was no literature report in LGFM, which may be of certain significance for the diagnosis and treatment of LGFM.