恶性纤维组织细胞型骨肉瘤9例电镜和免疫组化研究

Pathologic features of osteosarcoma with malignant fibrous histocytoma subtype : ultrastructural and immunohistochemical studies of 9 cases

目的 探讨恶性纤维组织细胞型骨肉瘤 (MFH typeOS)的形态特征、发生机制和诊断标准。方法 应用光镜、电镜观察 9例MFH typeOS组织学结构和细胞形态 ;应用组化和免疫组织化学技术检测MFH typeOS中酸性磷酸酶 (ACP)的活性和CD6 8、波型蛋白 (vimentin)、骨钙素 (osteocalcin ,OC)、骨黏连蛋白 (osteonectin ,ON)、嗜铬素A(CgA)和突触素 (Syn)的表达水平。结果 MFH typeOS由多种细胞组成 ,组织化学和免疫组化染色证实瘤细胞具有骨母细胞 (OB)、纤维母细胞 (FB)和组织细胞 (HC)特性 ,并证实肿瘤中有发育欠佳呈梭形的OB和骨样组织。其中 3例电镜观察到部分瘤细胞胞浆内有神经内分泌颗粒 ,对CgA和Syn的阳性表达率分别为 2 0 .0 %和 18.0 %。结论 MFH typeOS是多细胞成分肿瘤 ,少数细胞可伴有神经内分泌分化。形成机制是骨母细胞去分化 。

Objective To study the diagnosis, histogenesis and morphologic features of osteosarcoma with malignant fibrous histocytoma subtype ( MFH type OS). Methods Light microscopy and ultrastructural techniques were used to observe the histologic structures and cytomorphology of MFH typeOS. Histochemical and immunohistochemical stains were performed to determine the expression of ACP, CD68, vimentin, CgA, Syn, osteocalcin and osteonectin in 9 cases of MFH type OS. Results MHF type OS was composed of an admixture of various type of the tumor cells, histiocytes and fibroblasts. Osteoblasts and neoplastic osteoid were evident with osteocalcin and osteonection labelling. Electron microscopy demonstrated the neuroendocrine cells in 3 cases, in which CgA and Syn positive cells were 20.0% and 18.0% respectively. Conclusions MHF type OS is a polymorphic tumor composed of various tumor cells, including neuroendocrine cells. Dedifferentiation of osteroblasts with loss of osteroid secretion may lead to fibroblastic proliferation. MHF like features in osterosarcoma can be considered as the proliferation of osteoblastic lineage in a poor-differentiated stage.