请问这是腭腺的哪一种肿瘤，请给下诊断依据 ，越详细越好，急求！谢谢！！！

多形性腺瘤

多形性腺瘤

多形性腺瘤

多形性腺瘤

多形性腺瘤

恶性诊断的前提是浸润性生长，本例具有清楚的界限，甚至有包膜；肿瘤形态多样，有腺上皮、鳞状上皮和角质囊、粘液样基质，基本满足了多形性腺瘤的基本条件。下面这段话是摘自Fletcher 主编的Diagnostic Histopatholog of Tumors 3rd Ed，page 310，细细读来对涎腺肿瘤形态学中“浸润”的评价，对良恶性的判断很实用。
Assessment of the tumor interface with adjacent tissues,either at the macroscopic or microscopic level, is extremely important. Benign tumors are circumscribed, while malignant tumors have infiltrative borders, with the following exceptions: some acinic cell carcinomas and carcinomas ex pleomorphic adenoma may have circumscribed borders, while Warthin tumor complicated by infarction or inflammation can result in a lot of adhesions to surrounding tissue, mimicking a malignant neoplasm clinically or grossly. The pattern of infiltration also differs among different types of carcinomas – this tends to be of pushing type in epithelial-myoepithelial carcinoma, basal cell adenocarcinoma, myoepithelial carcinoma (except high-grade ones), and acinic cell carcinoma; whereas the other carcinomas usually exhibit irregular tongue-like infiltrative growth .

The importance of identification of invasion cannot be overemphasized. A presumptive diagnosis of adenoid cystic carcinoma must be wrong if tissue infiltration is not identified;similarly, this diagnosis should be viewed with some skepticism if extensive sampling of the tumor fails to reveal perineural invasion. Since adenoid cystic carcinoma may overlap morphologically with basal cell adenoma and sometimes pleomorphic adenoma, identification of invasion is one of the most important parameters for making the distinction. For some tumors, the presence of frank invasive features alone automatically moves the designation from the benign to the malignant category even if the tumor is morphologically blandlooking, for example, myoepithelial, basal cell and oncocytic neoplasms. The implication is that the tumor borders must be adequately sampled for examination. In some circumstances, a definitive diagnosis may not be possible without the opportunity to assess the tumor borders, such as in needle or incisional biopsies.

多形性腺瘤

界限很清楚，还是最常见的东东----------多形性腺瘤！

图片太小看不清。不能排除黏表