FCER2 and mantle cell lymphoma: One case of MCL in the previous validation showed an incorrect presumptive diagnosis, which was an atypical case of a cyclinD1-negative MCL (IHC results: CD20 +, Bcl-2 +, CD3 −, CD10 −, Bcl-6 −, CD23 −, MUM1 −, and p53 −).