涎腺含肌上皮细胞性肿瘤分化及起源之初探

Investigation on the differentiation and origination of the tumor comprised neoplastic myoepithalial cells from salivary glands

目的为了进一步探讨含肌上皮细胞性肿瘤的分化与起源，以及提高鉴别诊断水平。方法应用免疫组织化学对涎腺肌上皮瘤和多形性腺瘤的ＣＫ１８，Ａｃｔｉｎ表达以及组织学特征进行研究。结果从组织结构上看，肌上皮瘤由肿瘤性肌上皮细胞为主的“主质成分”和腺管样结构为辅的“次质成分”构成；多形性腺瘤则由粘液和软骨样物质组成的“细胞疏松区”和上皮性与肌上皮性两种成分组成的“细胞密集区”构成。从免疫组织化学表达上看，正常腮腺腺泡细胞既不表达ＣＫ１８，也不表达Ａｃｔｉｎ。正常腮腺腺管细胞同时表达ＣＫ１８和Ａｃｔｉｎ。在肌上皮瘤中，ＣＫ１８和Ａｃｔｉｎ均呈双重阳性表达。多形性腺瘤除导管内层细胞不表达Ａｃｔｉｎ外，其他结构成分均表达ＣＫ－１８和Ａｃｔｉｎ。结论涎腺含肌上皮细胞性肿瘤起源于闰管干细胞。闰管干细胞向肌上皮细胞分化占主导，则形成肌上皮瘤；若向导管上皮分化占主导，则形成腺瘤；如果同时双向分化，则形成多形性腺瘤。

Objective To probe into the differentiation and histogenesis of the tumors contained neoplastic myoepithalial cells from salivary glands and to improve the diagnosis of myoepithelioma. Methods The immunohistochemical expression of CK18,Actin and the histological characteristics of the tumors were observed. Results Myoepithelioma was comprised of predominant neophlastic myoepithalial cells and few adenoidal structure.Pleomorphic adenoma was made up of loose cellular district and concentrated cellular district.There were mostly mucoid and chondroid substance in the loose cellular district but epithelial and myoepithalial cells in the concentrated cellular district.CK18 and Actin expressed in the duct cells but the both not expressed in the alveoli cells.CK18 and Actin expressed in the myoepithelioma and pleomorphic adenoma but Actin not expressed in the duct lining cells of pleomorphic adenoma. Conclusions The tumors comprised noplastic myoepithalial cells from salivary glands derive from the stem cells of intercalated cells.The tumor should be myoepithelioma if the predominant differentiation of the stem cells is toward myoepithalial cells;it should be nonomorphic adenoma if that is toward duct luminal epithelial cells;pleomorphic adenoma should be differentiation toward both myoepithalial cells and duct epithelial cells.