腹外韧带样型纤维瘤病的MRI特征及与术后复发的相关性分析

Extra-abdominal desmoid-type fibromatosis: MR findings and related features of recurrence

目的总结腹外型韧带样纤维瘤病的MRI表现,探索其与肿瘤术后复发的相关性。方法回顾性分析2010年3月至2016年10月浙江大学医学院附属第二医院36例经手术病理证实的腹外型韧带样纤维瘤患者。患者年龄10~68岁,中位年龄28岁;男14例、女22例;病程1 d至8年;病变部位包括四肢20例、背部6例、胸壁3例、颈部1例、臀部6例。临床分期采用Church分期方法。MR平扫3例,平扫加增强33例。分析病灶部位、最大径、邻近结构受侵犯情况、强化程度及MRI征象。行常规SE序列、FSE序列矢状面质子密度加权成像(PDWI)、脂肪抑制短时反转恢复(STIR)序列及矢状面、冠状面、横断面T1WI脂肪抑制增强扫描。根据术后是否复发分为复发组15例和未复发组21例。比较2组MRI特征,包括筋膜尾征、触须征、脂肪分离征、病灶周围低信号环和邻近结构侵犯。连续性变量符合正态分布的采用独立样本t检验,分类变量采用χ^2检验,临床分期与复发相关性采用Spearman等级相关分析。结果36例患者的病灶相对于骨骼肌,平扫:T1WI呈等或稍低信号;T2WI呈混杂稍高信号2例、混杂高信号34例,内均见裂隙状低信号;增强扫描:显著强化22例,中度强化7例,轻度强化4例。Ⅰ期9例,其中复发组1例;Ⅱ期12例,其中复发组4例;Ⅲ期8例,其中复发组4例;Ⅳ期7例,其中复发组6例。每例MR影像表现均可见以下两种及以上征象;条带征36例,术后复发15例;触须征18例,术后复发15例;脂肪分离征12例,术后无复发病例;筋膜尾征15例,术后复发13例;病灶周围低信号环21例,术后复发2例。术前病灶侵犯邻近结构14例,术后复发13例;术后复发和未复发肿瘤的MR征象统计分析显示:MR征象中筋膜尾征、触须征、脂肪分离征、病灶周围低信号环和邻近结构侵犯在两组间差异具有统计学意义(χ^2值分别为21.424、25.714、12.857、21.424、24.699,P值均<0.05);性别、发病部位及病灶强化程度在两者间差异无统计学意义(χ^2值分别为1.626、0.823、3.465,P值均>0.05)。术后复发与病程、临床分期显著相关(χ^2=7.264,r=0.994,P<0.05)。结论腹外型韧带样纤维瘤患者的MRI特征为筋膜尾征、触须征、脂肪分离征、病灶周围低信号环和邻近结构侵犯。术前肿瘤影像表现邻近结构侵犯、触须征和筋膜尾征征象的患者术后复发率较高;表现周围低信号环征的患者术后复发率低,表现脂肪分离征征象本组无复发;病程长的肿瘤及Ⅲ期、Ⅳ期肿瘤复发率高。

Objective To explore the MR findings of extra-abdominal desmoid-type fibromatosis and the related features of recurrence. MethodsMRI and clinical data of 36 cases of extra-abdominal desmoid-type fibromatosis proved by surgical pathology were retrospectively reviewed between March 2010 and October 2016.The ages of the cases ranged from 10 years to 68 years. 14 males and 22 females were included with sex ratio 1∶1.57.the courses of the disease were varied from 1 day to 8 years. The stage was based on Church′s method. 3 cases were only with plain scan and other 33 cases with contrast enhancement. Sagittal or coronal T1WI, STIR-T2WI, PdWI and contrast enhanced T1WI in horizontal, sagittal and coronal view were examined on MR siganl 1.5T or 3.0T of GE Company. Two groups were divided based on the recurrence or not after surgery. The clinical and MR features were analyzed between the two groups with χ^2 test, t test or Spearman rank correlation analysis according to the data characteristics. ResultsCompared with signal intensity of muscle, 34 cases were isointense and 2 cases isointense with hypointense area on T1WI;34 cases were hyperintense and 2 cases hyperintense with hypointense area on T2WI. On contrast enhanced imaging, 22 cases were markedly enhanced, 7 cases moderately enhanced and 4 cases mildly enhanced.15 cases was with recurrence and 21 cases without recurrence. Infiltration of surrounding tissue was shown in 14 cases (38.9%), 13 cases with recurrence and 1 cases without recurrence. Band sign was shown in all cases. Tentacle sign was shown in 18 cases (50.0%), 15 cases with recurrence and 3 cases without recurrence. Split fat sign was shown in 12 cases (33.3%) and all without recurrence. Fascial tail sign was shown in 15 cases (41.7%), 13 cases with recurrence and 2 cases without recurrence. Hypointense ring around the tumor was shown in 21 cases (58.3%), 2 cases with recurrence and 19 cases without recurrence. The P value of tentacle sign, split fat sign, hypointense ring around the tumor, fascial tail sign and infiltration of surrounding tissue was less than 0.05. Gender, location and the degree of contrast enhancement was without difference of statistical significance between the two groups. There was significant correlation of the recurrence rate with the courses and the stage of the disease(χ^2=7.264, r=0.994, P<0.05). ConclusionsTentacle sign, fascial tail sign and infiltration of surrounding tissue were attributed to the estimate of recurrence of extra-abdominal desmoid-type fibromatosis, and Be features contributes to the diagnosis and therapy of extra-abdominal desmoid-type fibromatosis.