涎腺原发恶性肌上皮瘤19例的病理诊断分析

De novo salivary malignant myoepithelioma: pathologic diagnosis of 19 cases

目的 探讨涎腺多结节形态原发恶性肌上皮瘤的病理特征。方法 光镜观察19例涎腺多结节形态原发恶性肌上皮瘤的组织学、细胞学结构,其中11例做Calponin、平滑肌肌动蛋白(SMA)、S-100、神经胶质酸性蛋白(GFAP)、细胞角蛋白、增殖细胞核抗原(PCNA)的免疫组化检测,3例做超微结构观察。结果 肿瘤上皮巢呈多结节生长,中央常伴坏死,肿瘤侵袭周围组织,细胞有异形,肿瘤细胞主要为上皮样细胞型,有较多肿瘤性基质形成。肌上皮性标记及部分细胞角蛋白、PCNA标记阳性。电镜下见肿瘤细胞内有肌微丝。结论 免疫组化染色及超微结构观察均支持肿瘤为肌上皮来源及恶性特征。

Objective To study the pathological characteristics of salivary malignant myoepithelioma with characteristic multinodular architecture. Methods To observe the histologic and cytologic characteristics of 19 cases of de novo salivary malignant myoepithelioma with multinodular growth pattern. Immunohistochemistry of calponin, SMA, S-100, GFAP, cytokeratin, PCNA was done on 11 cases and ultrastructure was observed on 3 cases. Results 19 tumors presented characteristic multinodular growth pattern, mostly accompanied by central necrosis. Neoplastic nests invaded the surrounding normal tissue and tumor cells displayed avariety of pleomorphism. Epitheliod cell was the most predominant cell type. Tumor-related extracellular matrix formation was revealed among tumor cells. Immunohistochemical staining demonstrated that the tumor cells were positive for calponin, SMA, S-100, GFAP, AE1/AE3, CKH and PCNA. Myofilaments were found in neoplastic cell cytoplasm under the electron microscope. Conclusion Histologic and cytologic observation, immunostaining and ultrastructural study all supported the myoepithelial and malignant nature of the tumor.