侵袭性骨母细胞瘤的影像诊断与鉴别诊断

Imaging diagnosis and differential diagnosis of aggressive osteoblastoma

目的分析侵袭性骨母细胞瘤(aggressive osteoblastoma,AO)的影像学表现,总结AO的影像学特点及鉴别诊断要点。方法回顾性分析经病理证实的7例AO的X线、CT和MRI,分析影像学表现包括:发病部位、骨质破坏情况、病变内的密度、病变区的MR信号特点及周围侵袭性特点。结果7例AO患者中,男性4例,女性3例,年龄为13~56岁,中位年龄32岁。本组7例AO的发病部位是椎体5例,肱骨及肩胛骨各1例。7例AO均表现为膨胀性骨质破坏、骨皮质不完整,6例AO病变内有钙化或骨化,5例AO有厚薄不均匀的肿块影,3例AO病变累及邻骨,2例AO具有较少软组织水肿,1例AO可见骨膜反应。MR表现为T1WI呈不均匀等或低信号,T2WI呈不均匀低、等或高信号,钙化及骨化在T1WI和T2WI均为低信号,增强检查呈不均匀强化,2例病变区可见液液面(合并动脉瘤样骨囊肿)。结论AO是一种罕见的骨肿瘤,影像学表现有一定的特点:呈膨胀性骨质破坏,病变范围大,皮质不完整,病灶内钙化或骨化。AO应与骨巨细胞瘤、软骨母细胞瘤、骨肉瘤及转移瘤相鉴别。

Objective To analyze the imaging features of aggressive osteoblastoma(AO)and summarize its imaging characters and differential diagnosis.Methods Retrospectively analyzed the X-ray,CT and MRI of 7 cases of AO were confirmed by pathology,and analyzed the imaging findings,including the location of the tumor,the destruction of the bone,and the density in the lesion,characteristics of magnetic resonance signals and range of encroachment.Results There were 4 males and 3 females,aged from 13-56 years old,median age 32 years old.There were 5 cases occurred at vertebra,1 case occurred at scapular and 1 case occurred at humerus.X-ray and CT showed expansive bone destruction and cortical disruption.Six cases showed calcification or ossification within the lesion,5 cases showed soft tissue mass around the lesion,3 cases with adjacent bone involved,2 cases with less edema of bone marrow,1 case with periosteal reaction.MRI showed moderate and low mixed signals on T1WI,and showed heterogeneous signals on T2WI,low signal of calcification or ossification on both on T1WI and T2WI,and heterogeneous enhancement were observed in AO,liquid and liquid surface in 2 lesions(combined with aneurysmal bone cyst).Conclusion AO is a rare bone tumor with strong local aggressiveness,there were some imaging features of AO:the lesions of AO showed large expansive destruction and the cortex is incomplete,and calcification or ossification within the lesion.AO should be distinguished from giant cell tumor,chondroblastoma,osteosarcoma and bone metastases.