骨原发性原始神经外胚层瘤临床病理学研究

Primary primitive neuroectodermal tumor of bone: a clinicopathological study of 12 cases

目的 探讨骨原发性原始神经外胚层瘤 (PNET)临床病理特点和鉴别诊断要点及组织发生。方法 观察与分析 12例骨原发性PNET的临床特征、组织学特征及S P法免疫组化标记 ,并对其中 4例进行电镜观察。结果 PNET好发于男性青少年〔9～ 2 9(平均 17 7)岁〕的长骨。组织学特征 :肿瘤由大小一致的、原始的小细胞弥漫分布 ,纤维性条索将其分隔成不规则片块状 ,可形成Homer Wright菊形团。免疫组化标记 :CD99阳性 ,NSE、Syn及S 10 0蛋白部分阳性 ,Vim均阳性表达。电镜下瘤细胞形态较原始 ,可见线粒体、发育不良及神经分泌颗粒。结论 该肿瘤是一种少见的、好发生于男性青少年、组织学形态原始的、向神经外胚层分化的、具有高度侵袭性生长的。

Purpose To investigate the clinicopathological features, histogenesis of primary primitive neuroectodermal tumors (PNET) of bone and differential diagnosis from other small cell tumors. Methods Twelve cases of PNET were observed on histolo gic features and immunohistochemical staining by S P technique. Four cases were studied by electron microscope. Results Twelve cases of PNET, included 8 men and 4 women, aged 9～29 years (mean, 17 7 years). The long tubular bones were the most commonly affected site in PNET of bone. Histologic feature was uniform small cell presented in diffuse growth, irregular lobular pattern separated by fibrous and Homer Wright rosettes or pseudorosettes. Immunohistochemical study revealed always positive staining for vimentin, intense positive for CD99, and positive for Syn, NSE and S 100 protein. Ultrastructure showed fairly primitive differentiation. Dense neuro secretory granules in cytoplasm could be seen. Conclusions This is a rare kind of primary bone tumor with primitive morphology differentiates to neuroectoderm and most commonly occurred among youths. The biologic behavior shows highly aggressive with a poor prognosis.