Clinicopathologic Analysis Of Salivary Mass-type Lymphoepithelial Lesions And Primitive Investigation Of The Mechanism Of Malignant Transformation Of The Lesions

PURPOSES: To identify the clinicopathologic features,mechanism of malignant transformation,and auxiliary diagnosis method of mass-type lymphoepithelial lesion(LEL)in salivary gland.METHODS: Analyzing the subtype and clinicopathologic features of mass-type lymphoepithelial lesion in salivary gland between 2005～2017;investigating the clinicopathologic features and survival analysis of extranodal marginal zone lymphoma of mucosa associated lymphoid tissue B cell lymphoma(MALT lymphoma)between2005～2013;exploring the translocation of MALT1,trisomy 3 and trisomy 18 using fluorescence in situ hybridization(FISH)in MALT lymphoma.Evaluating the efficacy of double-stained immunohistochemistry(DIHC)in the diagnosis of mass-type LEL by different combination of antibody and chromogenic reagent.RESULTS:1.Among the 252 cases of mass-type LEL in salivary gland,BLEL were 113(113/252,44.8%),55.2% were BLEL accompanying with MALT lymphoma(BLEL/MALT,120)and BLEL accompanying with LEC(BLEL/LEC,120).There was a higher malignant ratio in the patients of malignant lesion with mass diameter >2cm(P=0.001).All the 19 patients with BLEL/LEC had EBV infection and without the history of SS.The molecular detection played an important role in diagnosis of malignant transformation.2.The risk of developing MALT lymphoma for the patients with BLEL is 23 times comparing to the patients without BLEL in salivary gland.Both the 2 cases of MALT lymphoma with high grade transformation were diffuse hyperplasia(P=0.047)and had a higher risk of occurrence(P=0.032).3.7.1% of the MALT lymphoma in salivary gland had the translocation of MALT1 gene and was prevalent in the male than in female(P=0.017).58.8% of the MALT lymphoma displayed trisomy 3 and the patients with trisomy 3 had a lower ratio with SS(P=0.038).10.0% of the MALT lymphoma showed trisomy 8,which was correlated with the recurrence of tumor(P=0.007).8 cases(11.4%)manifested 2 kinds of genetic abnormalities and most of them proved to be diffuse hyperplasia(P=0.007).4.The best combination for DIHC was Ki-67+DAB,and then AE1/AE3 or CD20+AEC.CONCLUSIONS:In salivary mass-type LEL,the malignant type is more common,the diameter of mass >2cm indicates a higher probability of malignant transformation,which most of them are MALT lymphoma.The patients with BLEL have a higher ratio of developing MALT lymphoma.The formation of BLEL/LEC is correlated with the infection of EBV,instead of SS.The diffuse hyperplasia of MALT lymphoma is easier to transition to high grade and relapse.Trisomy 3 is the most common genetic abnormalities in MALT lymphoma,the trisomy 18 can be the indicator of tumor relapse.Among MALT1 gene translocation,trisomy 3 and trisomy 18,trisomy 3 with another kind of genetic abnormalities have a higher ratio of high grade transformation.The molecular detection played an important role in the diagnosis and primitive investigation of mechanism of malignant transformation of masstype LEL.DIHC technique has better diagnostic value for mass-type LEL.