CD5 and mantle cell lymphoma: At most institutions, the diagnosis of MCL relies on demonstrating the classic histopathologic features and tumor cell immunophenotype (CD5+, cyclin D1+, CD23−, SOX11+/−), but many also perform IGH/CCND1 dual-color dual-fusion fluorescence in situ hybridization (FISH) and/or CCND1 break-apart probe studies to confirm the diagnosis.