滑膜肉瘤的不典型影像表现

Atypical Imagingm Anifestations of Synovial Sarcoma

目的探讨滑膜肉瘤(SS)的不典型影像学表现。方法回顾性分析2013年1月至2018年4月我院经病理证实的影像表现不典型的16例(男9例,女7例)SS患者的临床及影像资料。X线平片检查16例,CT平扫9例,MRI平扫及增强检查16例。由2名副主任医师对影像资料进行评价,包括病灶生长部位、数目、大小、形态、边缘、灶周水肿、密度、有无钙化及钙化形态、MR信号特点及强化方式等。结果不典型影像表现主要包括生长部位的不典型和影像特征的不典型。2例同时具有生长部位不典型及影像特征不典型的特点。⑴部位不典型6例。脊柱旁2例(颈椎旁1例,胸椎旁1例),腹股沟区2例,大腿中段深部肌肉间隙1例,足底、外展肌肌内1例。⑵影像特征不典型12例,包括信号不典型和强化不典型。5例同时具有信号不典型及强化不典型的特点。4例巨大病灶(直径约8-14cm),其内信号均匀,呈均匀等T1、稍长或长T2信号改变。1例病灶T2WI呈均匀稍低信号。7例增强后呈轻度强化。4例巨大病灶(直径约8-14cm)增强后呈均匀强化,其内未见明确坏死、囊变所致的无强化区。1例增强明显强化,强化程度与邻近血管相仿。结论不典型滑膜肉瘤易被延迟诊断或误诊,全面了解其影像表现,有助于提高该病的正确诊断及鉴别诊断水平。

Objective To investigate the atypical imaging manifestations in patients with synovial sarcoma(SS). Methods The clinical and imaging manifestations of 16 patients(9 males, 7 females) with pathologically confirmed atypical SS(from Jan 2013 to Apr 2018) were analyzed retrospectively in this study. We analyzed the imaging examinations performed in these patients, including plain radiography(n=16), computed tomography(n=9) and magnetic resonance imaging(n=16). The imaging manifestations including the location, number, size, shape, edge, peripheral edema, density, calcification, signal intensity, enhancement patterns of lesions were evaluated by two deputy chief radiologists. Results he atypical imaging manifestations included atypical location and atypical imaging features. Both atypical location and atypical imaging features were owned for 2 cases. ⑴ atypical location: For the 6 patients showed atypical location, involving beside the cervical vertebra(n=1), beside the lumbar vertebra(n=1), inguinal region(n=2), deep muscular space of the middle thigh(n=1) and musculus abductor hallucis(n=1). ⑵ atypical imaging features: 12 cases were found with atypical imaging features including atypical signal and atypical enhancement patterns. Both atypical signal and atypical enhancement patterns were owned for 5 cases. MRI signal intensity of 4 cases of huge lesions(8 to 14 cm in diameter) appeared homogeneous isointensity on T1 WI, hyperintensity or hyperintensity on T2 WI. MRI signal intensity of 1 case appeared hypointensity or hyperintensity on T2 WI. These was slightly homogeneous enhancement of 7 cases after administration of contrast medium. 4 cases of huge lesions(8 to 14 cm in diameter) appeared homogeneous enhancement without the area of necrosis and cystoid variation. One case demonstrated obvious enhancement with great resemblance signal intensity of vessel. Conclusion Atypical synovial sarcoma is easy to be delayed or misdiagnosed. A comprehensive understanding of its imaging manifestations will help to improve the correct diagnosis and differential diagnosis of the disease.