继发性骨肉瘤的临床特点及影像学表现

目的:分析继发性骨肉瘤的临床特点及影像学表现.方法:回顾性分析经手术病理证实的25例继发性骨肉瘤患者的病例资料.25例均行X线及CT检查(5例行增强CT),16例行MRI增强检查.结果:本组患者的中位年龄45岁(14～76岁),中位恶变时间为8年(0.5～18.0年).25例中骨纤维结构不良、骨母细胞瘤等良性肿瘤或肿瘤样病变恶变12例,表现为溶骨性破坏、软组织肿块形成及病灶迅速增大等与原发骨肉瘤相仿的影像学改变;骨巨细胞瘤植骨后恶变继发性骨肉瘤8例、金属植入相关的继发性骨肉瘤2例,均表现为移植骨吸收、周围出现明显软组织肿块及肿瘤骨形成;放疗后继发性骨肉瘤2例,以成骨性骨质破坏为主;Paget病继发性骨肉瘤1例,表现为在患骨增粗、不规则变形基础上,出现溶骨性破坏及软组织肿块.病理结果:镜下有不同程度的细胞异形性、肿瘤骨形成.所有病例术后随访时间为1.5～12.0年(平均3.4年),8例出现肺部转移.结论:病理组织学上继发性骨肉瘤与原发性骨肉瘤无明显差异,但结合其临床资料及影像学表现可明确诊断.

Clinical and radiological features of secondary osteosarcoma

Objective:To analyze the clinical and imaging features of secondary osteosarcoma.Methods:The the clinical,imaging features and pathological manifestations of 25 patients with secondary osteosarcoma proved by surgical pathology were retrospectively reviewed.All patients were examined with X-ray and CT (5 enhanced CT) and 16 underwent enhanced MRI.Results:The median age was 45 years old (14～76 years old),and the median progression time was 8 years (0.5～18.0 yrs).In all 25 cases,osteosarcoma secondary to bone fibrous dysplasia,osteoblastoma and other benign tumors or tumor-like lesions were seen in 12 cases,showing osteolytic destruction,soft tissue mass formation and rapid enlargement of lesions with similar imaging findings as primary osteosarcoma;osteosarcoma secondary to giant cell tumor after bone transplantation was seen in 8 cases,or secondary to metal implantation was seen in 2 cases,all showing absorption of bone graft,apparent soft tissue mass and tumor bone formation;radiation-induced secondary osteosarcoma was seen in 2 cases,characterized by osteogenic destruction.One case was Paget disease associated with secondary osteosarcoma,showing osteolytic destruction,soft tissue mass formation based on bone enlargement and irregular deformation.The pathological results showed different degrees of abnormal cells and tumor bone formation under the microscope.All cases were followed up for an average of 3.4 years (1.5 ～ 12.0 yrs),and 8 patients had pulmonary metastases.Conclusion:The histopathology between secondary osteosarcoma and primary conventional osteosarcoma was not significantly different,but in combination with the clinical data and imaging findings secondary osteosarcoma can be clearly diagnosed.