原发性骨外骨肉瘤的影像诊断(附7例报道及文献复习)

Imaging diagnosis of primary extra-skeletal osteosarcoma: report of 7 cases

目的探讨原发性骨外骨肉瘤的影像表现及临床特征,提高对该病的认识。方法回顾性分析7例经病理证实的原发性骨外骨肉瘤的临床及影像资料,并结合相关文献复习。结果 7例原发性骨外骨肉瘤均行CT检查,4例行MRI检查,其中4例行CT增强检查,2例行MRI增强。发病部位分别位于左侧股内侧肌、左侧膝部髌下软组织、前纵隔、乳腺、右肾、腹膜后间隙及膀胱各1例。患者均无骨的原发骨肉瘤病史,临床表现各不相同;CT上均表现为骨外的一不规则软组织肿块影,5例肿瘤内伴有结片状钙化或瘤骨成分,4例CT增强呈明显不均匀强化,2例可见斑片状坏死,2例可见肿瘤供血动脉;4例MRI平扫均表现为一不规则软组织信号肿块影伴信号不均,2例MRI增强呈明显不均匀强化。7例患者均经病理证实为原发性骨外骨肉瘤。结论原发性骨外骨肉瘤临床特征缺乏特异性,其影像特点表现为骨外的不规则软组织肿块伴有钙化或瘤骨成分,但诊断特异性低,确诊主要依靠病理活检。

Objective To investigate the imaging manifestations and clinical features of primary extra-skeletal osteosarcoma.Methods The clinical data, CT（7） and MRI（4） findings of primary extra-skeletal osteosarcoma in 7 patients were retrospectively analyzed. Results 4 cases in CT were contrast enhanced and 3 cases in MRI were contrast enhanced. The osteosarcoma involved the left vastus medialis, left infra-patellar soft tissue, anterior mediastinum, breast, right kidney, retroperitoneum, and bladder without primary osteosarcoma of bone. The irregular soft tissue mass was entirely shown on CT in all patients with nodal calcification or tumor ossification （5）, heterogeneous enhancement （4）, or patchy necrosis （2）. The supply arteries were found in 2 tumors. MRI showed irregular soft tissue mass with heterogeneous signal intensities （4） and enhancement （3）. Conclusion The clinical features of primary extra-skeletal osteosarcoma are nonspecific. The main imaging manifestations are an irregular soft tissue mass with calcification or ossification. Diagnosis requires histological confirmation.