软骨黏液样纤维瘤的影像学表现

Imaging findings of chondromyxoid fibroma of bone

目的:分析软骨黏液样纤维瘤影像表现与病理的关系,以提高诊断准确性。方法:回顾性分析经手术病理证实的骨骼软骨黏液样纤维瘤11例,术前分别经X线平片,CT平扫,MRSET1WI、T2WI,增强T1WI扫描,仔细复习影像学结果并与手术病理作对照。结果:11例原发性骨骼软骨黏液样纤维瘤中,发生于长管状骨7例,骨盆2例,颅骨1例,脊柱1例。所有肿瘤呈膨胀性溶骨性骨质破坏,内可见骨性分隔9例,周边骨质硬化8例,软组织肿块3例。肿瘤直径3.2～16.9cm,平均4.7cm。7例位于长管状骨者,所有病灶位于干骺段,破坏区呈椭圆形,长轴与骨长轴一致,内可见增粗骨小梁,皮质膨胀,显著骨内膜增生,少数可见弓环状钙盐沉着。位于骨盆的2例中,1例呈地图样囊性骨质破坏,内可见少许分隔,并见硬化边;1例以巨大软组织肿块为主,境界欠清,可见明显弓状和环状钙化。1例位于鞍区,CT检查显示病灶密度低于肌肉密度,内隐约可见分隔和钙化,MRT1WI为低信号,T2WI显著高信号,内均可见低信号分隔,增强扫描分隔明显强化。1例位于腰椎的附件,MRT1WI为等信号,T2WI显著高信号,增强隐约可见强化。结论:软骨黏液样纤维瘤多位于长管状骨的干骺段,呈偏心性、膨胀性、溶骨性骨质破坏,皮质膨出、增粗小梁以及大量骨内膜增生为其显著特点,病灶内软骨钙化少见。少数可侵犯骨盆、脊柱附件以及颅底等不规则骨,多呈不规则圆形或地图状,边缘常有硬化。软骨黏液样纤维瘤由软骨样物质、黏液样结构和纤维按不同比例构成,不同肿瘤三者比例不同,某一种成分比例过多可能影响诊断。

Objective： To explore the imaging features of chondromyxoid fibroma of bone and evaluate their clinical value. Methods： Eleven cases with chondromyxoid fibroma of bone confirmed by surgical pathology underwent radiography, CT plain scanning and MR SE-T1WI, SE-T2WI and SE-T1WI enhanced scanning before operation, the imaging data was reviewed and 1 analysed retrospectively in comparison with surgical and pathological results. Results： The lesions in seven cases of 11 chondromyxoid fibroma with well defined osteolytic destruction were located at the metapbysis of the long tubular bone, in 2 cases the lesion was in pelvis, 1 case in skull, the other case in vertebrae. The diameter of the tumor ranged from 3.2cm to 16.9cm, with a mean diameter of 4.7cm. When located in a long tubular bone, chondromyxoid fibroma were generally eccentrically situated at the metaphysis, radiolucent and elongated in shape, cortical expansion, exuberant endosteal sclerosis, and coarse trabeculation, with small area of ring- and arc-like calcification, thin sclerotic rim separated the tumor from adjacent normal bone, there may he little periosteal reaction and small soft tissue masses. The CT value was similar to muscle and CT is optimal to detect the matrix mineralization. MR imaging depicted low signal intensity with well defined rim on T1WI, high signal intensity on T2WI. Conclusion： The imaging manifestations of chondromyxoid fibroma were specific to some extent. Combined utilization of plain X-ray, CT, and MRI is helpful for the diagnosis and differential diagnosis of chondromyxoid fibroma.