隆突性皮肤纤维肉瘤的影像表现及其病理基础

Imaging features and relevant pathological changes of dermatofibrosarcoma protuberans

目的:探讨隆突性皮肤纤维肉瘤(Dermatofibrosarcoma protuberans,DFSP)的CT、MRI表现及其病理基础,提高对本病的诊断水平。方法:回顾性分析16例经手术病理证实的DFSP患者资料,就其影像及病理进行分析总结。结果:15例位于皮肤或皮下脂肪内,1例位于浅筋膜下,其中发生于盆壁4例,腹壁4例,头颈部3例,大腿3例,乳腺1例,阴囊1例;8例呈类圆形,7例呈不规则形,其中6例合并子结节外突征,1例呈梭形,病灶最大径2.9~10 cm,平均5.6 cm,肿瘤边界均欠清;4例CT平扫呈均匀低密度,CT值约为23~37 HU,其中1例增强扫描呈较明显强化;T1WI上,11例呈稍低信号,1例呈等信号;T2WI上,4例呈均匀高信号,8例呈混杂高信号,7例呈DWI高信号,增强扫描5例呈不均匀明显强化;肿瘤具有侵袭性,其中14例见“脂肪尾征”,12例见“皮肤尾征”,10例见“筋膜尾征”;镜下见梭形肿瘤细胞围绕血管呈席文状排列,在真皮、皮下组织内浸润生长,其中1例肿瘤实质内见黏液样基质区,1例伴有纤维肉瘤样变区,1例肿瘤两者兼有,免疫组化CD34均呈阳性。结论:DFSP的影像表现具有一定特征性,可为术前定性及手术方式制定提供参考,最终确诊仍依赖病理。

Objective:To investigate the CT and MRI features and relevant pathological features of dermatofibrosarcoma protuberans(DFSP),so as to improve the level of diagnosis of this disease.Methods:The CT and MRI findings and pathological results of 16 cases with DFSP proved by pathology were retrospectively analyzed.Results:Fifteen cases were located in the skin or subcutaneous tissues and 1 case under the superficial fascia,which 4 cases occurred in the pelvic wall,4 cases in the abdominal wall,3 cases in the head and neck,3 cases in the thighs,1 case in the breast and 1 case in the scrotum.Eight cases were round-like shapes,7 cases were irregular shapes,of which 6 cases were complicated with“nodular protruded outward”,1 case was fusiform.The maximum diameter of tumors was 2.9~10 cm,with an average of 5.6 cm.The boundaries of the tumors were not clear.On CT plain scan,4 cases showed homogeneous low-density,CT values were about 23~37 HU,of which 1 case was homogeneous enhancement.On T1WI,11 cases showed slightly hypointensity,1 case showed isointensity.On T2WI,4 cases displayed homogeneous hyperintensity,8 cases showed inhomogeneous hyperintensity,7 cases showed hyperintensity on DWI,5 cases presented heterogenous enhancement.14 cases showed“fat tail sign”,12 cases showed“skin tail sign”,and 10 cases showed“fascia tail sign”.Under the microscope,spindle shaped tumor cells arranged in a curved pattern around the blood vessels and infiltrated in the dermis and subcutaneous tissue.There was mucoid matrix in the parenchyma in 1 case,1 case with fibrosarcoma-like area,1 case with mucous area and fibrosarcoma-like area.The immunohistochemical reports of all cases were positive for CD34.Conclusion:The imaging manifestations of DFSP have certain characteristics,which can provide reference for preoperative diagnosis and operation mode formulation.The final diagnosis still needs pathological and immunohistochemical examination.