中老年患者骨肉瘤的影像学诊断价值

Imaging characteristics and misdiagnosis of osteosarcoma in the middle and old age

目的探讨中老年骨肉瘤的发病特点与影像学特点。方法选取经手术病理证实的56例中老年患者骨肉瘤的影像学表现。本组男性34例,女性22例,年龄41~76岁,平均年龄54岁。结果肿瘤发病部位:长骨33例,扁骨17例,脊柱3例,跗骨2例,髌骨1例。肿瘤影像学分型:成骨型33例、混合型8例、溶骨型15例。本组继发性骨肉瘤7例,其中继发于骨纤维异常增殖症5例、骨母细胞瘤1例、陈旧性骨折1例。27例缺少典型的瘤骨,CT对肿瘤骨的显示最佳,仅行MRI检查的4例患者均被误诊。术前诊断:诊断骨肉瘤26例(仅占46%),只诊断恶性骨肿瘤3例,误诊为转移瘤12例、软骨肉瘤6例、骨巨细胞瘤4例、骨母细胞瘤和骨纤维异常增殖症各1例,误诊率为44.6%。病理诊断:普通型骨肉瘤44例,骨纤维异常增殖症恶变3例,特殊类型包括成纤维性骨肉瘤3例、纤维母细胞型2例、软骨母细胞型2例、富巨细胞型和去分化型各1例。结论中老年患者骨肉瘤发病部位除股骨最常见外,扁骨和不规则骨也较多,此外,继发性骨肉瘤较多,瘤骨和骨膜反应不典型者较多,误诊率较高。因此,重新认识老年患者骨肉瘤的特点,注意识别瘤骨,各种检查相互印证,方能减少误诊。

Objective To investigate the characteristics of osteosarcoma in the middle and old age patients,and analyze the causes of misdiagnosis.Methods We retrospectively analyzed imaging features of 56 cases of osteosarcoma which confirmed by operation and pathology.In this group,male 34 and female 22,aged 41~76 years old,average 54 years old.Results Tumor location long bone in 33 cases,flat bone in 17 cases,spine in 3 cases,tarsal in 2 cases,patella in 1 case.The classification of tumor imaging osteogenic type in 33 cases,mixed type in 8 cases,osteolytic type in 15 cases.In this group,there were 7 cases of secondary osteosarcoma,including 5 cases of osteofibrodysplasia,1 case of osteoblastoma and 1 case of old fracture.Twenty-seven cases were lack of typical tumor bone,and CT is the best mathod to show tumor bone.Four cases who only underwent MR examination were all misdiagnosed.Preoperative diagnosis 26 cases(46%)were diagnosed as osteosarcoma,3 cases were only diagnosed as malignant bone tumor.Twelve cases were misdiagnosed as metastasis,6 cases as chondrosarcoma,4 cases as giant cell tumor,1 case as osteoblastoma and 1 case as fibrous dysplasia,the misdiagnosis rate was 44.6%.Pathological diagnosis 44 cases of common osteosarcoma,3 cases of bone fibrosis,3 cases of special types including fibrogenic osteosarcoma,2 cases of fibroblastic type,2 cases of chondroblastic type,1 case of giant cell rich type and 1 case of dedifferentiated type.Conclusion The most common position of osteosarcoma in the middle-aged and elderly is femur,while flat bones and irregular bones are also common.In addition,there are more secondary osteosarcoma.Atypical reaction of tumor bone and periosteum is common,with a high misdiagnosis rate.In order to reduce misdiagnosis,we should recognize the characteristics of osteosarcoma in the elderly again,pay attention to the recognition of the tumor bone and confirm each other with various examinations.