富于巨细胞的骨肉瘤4例临床病理观察

Giant cell rich osteosarcoma: a clinicopathological observation of 4 cases

目的:探讨富于巨细胞的骨肉瘤(GCRO)的临床病理特征、诊断与鉴别诊断。方法:结合临床资料及影像学所见,分析4例GCRO的组织病理特征并复习相关文献。结果:患者包括2男2女,其年龄分别为35岁、50岁、59岁及15岁。发病部位股骨下段2例、胸椎及胫骨下段各1例。X线显示偏心性溶骨性病变,不仅表现为渗透性或虫噬样破坏,而且伴有骨膜反应及软组织肿块。大体上灰褐色肿瘤质软硬不均,伴有灶性出血、坏死及囊形变。镜下肿瘤横穿骨皮质,浸润松质骨及小梁。在普通型骨肉瘤背景上,主要由大量良性多核巨细胞和肥胖的恶性梭形细胞构成。这些巨细胞有的类似破骨细胞,含有20个左右形态一致的小圆核。其间散在呈现骨源性分化肿瘤的嗜酸性骨样组织或骨基质;同时可见非典型细胞及核分裂。免疫组化示巨细胞CD68呈阳性,所有细胞表达vimentin阳性,但不表达CK及CD34。结论:GCRO是一种罕见的骨肉瘤亚型。易误诊为骨巨细胞瘤。充分理解其病理特点,有助于正确诊断。

Objective：To investigate the clinicopathologic features,diagnosis and differential diagnosis of giant cell rich osteosarcoma（ GCRO ）. Methods：Four cases of GCRO were analysed histopathologically in combination with clinical data and image findings,and the related literature was reviewed. Results：The patients including two males and two females were admitted to the hospital for painful and palpable masses found in the bones. And their ages were 59,35,15,and 50 years,respectively. Sites of involvement were the distal femur each in 2,thoracic vertebra and distal tibia each in 1. The X-ray revealed an eccentric osteolytic lesion that not only presented with permeative/moth eaten distruction in the metaphysic,but also accompanied with periosteal reaction and soft-tissue mass. Grossly,the tumor was depicted as soft to firm in texture and grey to tan in color with foci of hemorrhage,necrosis and cystic appearance. Microscopically,the tumor transgressed the cortex and infiltrated in the cancellous bone and trabeculae. It was com-posed predominantly of benign polynucleation giant cells,some just like osteoclasts with about 20 uniformly small round nuclei,and malignant plump spindle -shaped cells in the background of conventional osteosarcoma. Mean-while,some scattered eosinophilic osteoid tissues or osseous matrix that indicating as an osteogenic differentiation was seen. And some cytologic nuclear atypia and mitoses were observed. Immunohistochemically,the giant cells were posi-tive for CD68. All cells of the tumor were positive for vimentin,yet negative for CK and CD34. Conclusion：GCRO is a subtype of osteosarcoma and easily mistaken as giant cell tumor of the bone. Full understanding the pathologic char-acteristics of the tumor is helpful to making correct diagnosis.