Though universal primers exist for disease-defining translocations and mutations, such as t(11;14) in MCL, t(14;18) in FL, and MYD88 mutation in primary central nervous system lymphoma (PCNSL), patient-specific primers developed using the initial tumor sample are required for detection of clonotypic immunoglobulin heavy chain (IgH VDJ) rearrangements. Here, MYD88 is linked to primary central nervous system lymphoma.