口腔颌面部Ewing肉瘤/原始神经外胚层瘤的临床病理学研究

目的提高对口腔颌面部Ewing肉瘤／原始神经外胚层瘤（Ewing肉瘤／PNET）的临床病理特征的认识，减少误诊。方法收集四川大学华西口腔医学院病理科1970年1月至2004年12月临床病理诊断符合Ewing肉瘤／PNET的病例共15例，年龄1～49岁，平均14．5岁，主要表现为肿胀，影像学可见骨质破坏。结合文献对其组织学特征进行分析，并行免疫组化LSAB法染色，抗体为CD99（12E7）、波形蛋白、神经冗特异性烯醇化酶（NSE）、S-100、突触素（Syn）、CD45（LCA）及结蛋白。结果①组织学特征：肿瘤主要由密集的小细胞组成，弥漫分布，纤维性条索将其分隔成不规则片块状，可见菊形团样结构，部分细胞含糖原。②免疫组化标记：所选7例CD99及波形蛋白均阳性，CD45、结蛋白均阴性；S-100阳性4例，NSE阳性3例，Syn阳性1例，2例对NSE、S-100、Syn均为阴性。结论口腔颌面部Ewing肉瘤／PNET极为少见，多为青少年，免疫组化可辅助诊断，p30／32^MIC2高水平表达对确诊有价值。

Clinicopathological study of Ewing's sarcoma/primitive neuroectodermal tumor in oral and maxillofacial region

OBJECTIVE: To study the clinicopathological features and diagnostic criteria of Ewing's sarcoma/primitive neuroectodermal tumor (Ewing's sarcoma/PNET) in oral and maxillofacial region. METHODS: There were 15 patients with Ewing's sarcoma/PNET in the last 35 years at our hospital, aged 1-49 years and mean 14.5 years. The most common manifestation was swelling of the affected region. The cases were analyzed and histological and immunohistochemical studies were also conducted to examine CD99 (12E7), Vimentin, NSE, S-100, Syn, CD45 (LCA), desmin. RESULTS: (1) The most common histological pattern of Ewing's sarcoma/PNET was a lobular arrangement of uniform, small, hyperchromatic cells in a fibrous background. Some of these tumors were rich in cytoplasmic glycogen. (2) Of the 7 cases, IHC was positive for CD99 (12E7) and Vimentin and negative for lymphoid (CD45), muscle (desmin) markers. S-100 was positive in 4 cases and NSE negative in 3, Syn positive in 1. NSE, S-100, Syn were all negative in 2 cases. CONCLUSIONS: Ewing's sarcoma/PNET is more common in teenagers and young people. Immunohistochemistry is essential to distinguish Ewing's sarcoma/PNET from other small round cell tumors. Immunohistochemistry is useful in the diagnosis.