膝关节色素沉着绒毛结节性滑膜炎的影像学和病理学表现

The imaging and pathological diagnosis of pigmented villonodular synovitis of knee joint

目的:探讨膝关节色素沉着绒毛结节性滑膜炎(PVNS)的影像学和病理学表现。方法:回顾分析20例经手术和病理证实的PVNS影像学和病理学资料,并进行总结。结果:①X线表现:20例中,关节间隙增宽3例和变窄7例;10例在髌骨上下囊区可见单个或多个密度增高的椭圆形或分叶形阴影;关节骨面破坏6例;②MRI表现中弥漫型9例,局灶型3例。弥漫型中可见关节腔积液,髌上囊中见低信号结节,交叉韧带表面有增厚的低信号滑膜覆盖,并见关节骨面破坏,病灶周围有硬化环。局灶型表现为单发性肿块。结论:膝关节PVNS的MRI表现具有特征性,与术中所见和病理大多相符,能够作出正确诊断。

Objective： Pigmented villonedular synovitis （PVNS） is a rare proliferative disorder of the synovium. The imaging and pathological represenations of pigmented villonodular synovitis of knee joint were discussed in this article.Methods：From Oct 1990 to June 2004, we retrospectively evaluated 20 patients with knee PVNS, that were treated with operation and diagnosis confirmed by histological examination. 12 cases were examined by MRI, and 3 of them received contras enhanced MRI. X-film were performed in all patients.Resuits： ①X-film showed that the intervals of the knee joint was normal in 14 cases, and widened in 3, narrow in 3 cases. The joint capsule were swollen in 15 patients, among them there were single or multi-hyperintens shadows around the joint could be seen in 10 cases. Bone erosive lesions were seen in the femoral condyle, patella and tibal plateau in 1,2 and 4cases respectively. There were sclerotic margins surrounding the lesions could see in 7; ② MRI in 12 patiegs showed diffuse form （9 cases） and localized form （3 cases）. In diffuse form of PVNS effosion appeared in all of the patients, and intermediate-to-low intensity signal nodules were displayed in the suprapatellar bursae in 3 cases, and low singal proliferative synovium covered on the surface of the cruciate ligments in 3 cases on T1WI. There were 15 bone erosive lesions in the femoral condyle, patella and tibal plateau. Low singal sclerotic margins surrounding the lesions were seen among 13. The low singal proliferative synovium and synovial nodules were enhanced after contrast administration in 3 patients. In localized form of PVNS in 2 cases, the single mass with joint effusion occurred;③ The nodules and villi, that characterized by deposit of intracellular heemosiderin, is the typical appearance of PVNS in the knee joint can be seen during operation. And these were accord with the MPd in same cases. Condusion：PVNS of the knee presents a difficult differential diagnosis. MR1 is able to diagnose PVNS by identifying the presence of heemosiderin precipitates within the nodules characterizing the PVNS, that accord with pathology and histology in many cases.