Immunohistochemical studies revealed that the tumor cells were diffusely positive for cytokeratin AE1/AE3 and cluster of differentiation (CD)99 antigen and focally positive for epithelial membrane antigen (EMA); the lymphocytes were positive for CD1a and terminal deoxynucleotidyl transferase (TdT) and CD20 (Fig. 3c–e). Here, MUC1 is linked to neoplasm.