Poster 078: Comparative Study of Lymphocytes Infiltrating Into Cystic and Solid Types of Warthin’s Tumor

Abstract

Warthin’s tumor (adenolymphoma) is clinically classified into the cystic and solid types. It is a matter of deep interest whether there is any difference in the infiltration of lymphocytes into respective types of the tumor. To examine the lymphocytes infiltrating into two cases of the tumor, one suffering from the cystic type and the other from the solid type, we performed an immunohistochemical staining with antibodies against lymphocyte markers, i.e., CD3, CD4, CD8, CD20 and CD68, in respective types of the tumor. Here we report the results of this comparative study for the infiltrating lymphocytes between the two types of Warthin’s tumor. Both cases were adult male patients and had the tumor unilaterally. We made paraffin sections of the tumors and performed immunohistochemical staining using antibodies to these CD antigens. After immunohistochemical staining, we examined the expression patterns of the CD antigens in both solid and cystic types under light microscopy, and compared the findings of each type. CD4 which is the marker for T cells, was found in the lymphocytes localized as follicles in the specimens of the solid type tumor. Both CD3 and CD8 were found in the lymphocytes in both solid and cystic types, but the quantity of CD8 was reduced as compared to that of CD3. In both types of the tumor the lymphocytes positive to CD20, a B cell marker, were intermingled with those negative to it, and there was no difference in positive staining for CD20 between the two types. Monocyte/macrophage maker CD68 was negative for the cells in the solid type, while the cells with positive staining to CD68 were found in the cystic type. These results showed that there were differences in the infiltrating lymphocytes between the solid and cystic types of adenolymphoma; CD4 positive T cells were mainly found in solid type tumor and CD68 positive monocyte/macrophage were predominantly found in cystic type tumor. These results suggest that the difference in the infiltration of lymphocytes would be involved in development of the morbidity of Warthin’s tumor.