摘要目的 探讨富于巨细胞的骨肉瘤(GCRO)和骨巨细胞瘤(GCT)的临床病理特征及鉴别诊断.方法 从临床、影像学、病理形态及免疫表型等方面对18例GCRO和118例GCT进行对比分析和研究.结果 GCRO 18例,平均年龄24.6岁,大多发生于长骨干骺端(15/18),影像学表现为渗透性骨质破坏,肿瘤边界不清,伴或不伴骨膜反应和软组织肿块.镜下大量反应性破骨细胞样巨细胞之间的肿瘤性单核细胞有不同程度异型,可见病理性核分裂象,并产生幼稚的肿瘤性骨样基质.GCT118例,平均年龄34.5岁,大多发生于长骨骨端(108/118),影像学表现为膨胀性地图样骨质破坏,病灶边缘清楚,早期骨皮质连续,侵袭期骨皮质破坏,偶有软组织肿块.镜下由卵圆形或短梭形的单核间质细胞、多核巨细胞和单核巨噬细胞组成,单核间质细胞边界不清,无明显异型和病理性核分裂象,单核间质细胞多表达p63(83.9％,99/118).肿瘤边缘区域常有反应性骨.结论 GCRO是普通型骨肉瘤中的罕见组织学亚型,与侵袭期GCT在临床、影像学及病理学改变上都有交叉.虽然单核肿瘤细胞的异型性、病理性核分裂象及其直接形成的肿瘤性骨样组织这三项GCRO的主要诊断依据是GCT所缺乏的,但这三项特征在活检组织中并不一定都出现,综合分析资料对确定诊断尤为重要.

abstractsObjective To study the clinicopathologic features and differential diagnosis of giant cell-rich osteosarcoma (GCRO) and giant cell tumor of bone (GCT).Methods The clinical,radiologic,pathologic and immunohistochemical features of 18 cases of GCRO and 118 cases of GCT were evaluated.Results The mean age of patients with GCRO was 24.6 years.Fifteen of the 18 cases arose in the metaphysis of long bones.GCRO presented as a large poorly-defined mixed lytic and blastic mass,associated with cortical destruction and formation of large soft tissue component.Histologically,GCRO was characterized by a predominance of numerous osteoclast-like giant cells admixed with scanty osteoid which was formed by neoplastic cells in different levels of anaplasia and pleomorphism.In the 118 cases of GCT studied,the mean age of patients was 34.5 years.Most of them (108 cases) arose in the epiphyseal region of long bones.They usually presented as expansile eccentric and osteolytic lesions.Invasive GCT displayed local cortical destruction.Histologic examination of GCT revealed the presence of large number of osteoclastlike giant cells and mononuclear stromal cells.The mononuclear stromal cells possessed poorly defined cytoplasm,showed little cytological atypia and did not carry atypical mitotic figures.They were positive for p63 (83.9％,99/118).Reactive bone could be observed at the periphery.Conclusions GCRO represents a special form of osteosarcoma which shows overlapping clinicopathologic features with invasive GCT.The presence of nuclear atypia,atypical mitoses and osteoid matrix produced directly by neoplastic cells are more in favor of GCRO.These features however may not be demonstrated in full in limited small biopsy samples.It is thus important to analyze all clinical,radiologic and pathologic features before a definitive diagnosis is made.