MCL is a mature B-cell lymphoma characterized by expression of CD5 and cyclin D1.[7] Cyclin D1 expression is a result of t(11;14)(q13:q32) translocation between the IGH gene and the CCND1 gene.[8, 9] However, the diagnosis of MCLs can be complicated in some cases. This evidence concerns the gene CD5 and mantle cell lymphoma.