On histopathological examination, the tumor was diagnosed as chondroma (Figure 3L); Vimentin (Figure 3M), Ki-67 (6%) (Figure 3N), SOX-9 (Figure 3O), and S-100 (Figure 3P) stained positive, but CK, CK18, EMA, CD34 and GFAP stained negative. This evidence concerns the gene KRT18 and chondroma.