CD5 and neoplasm: Immunohistochemical results showed that tumor cells were diffusely positive for CD20 (Figure 1C); positive for CD79α (Figure 1D); MYC (+, approximately 80%) (Figure 1E); CD10 (Figure 1F); focal moderately positive for Bc1-6 (Figure 1G), focal positive for Mum-1 (10% of cells) (Figure 1H); negative for CK, CD3, CD5, CD30, BCL-2 (Figure 1I); and strongly positive for Ki-67 (nearly 100%) (Figure 1J).