3.1.1 IgM paraprotein identified on serum immunofixation electrophoresis OR light chain-restricted CD20+ lymphoplasmacytic population on biopsy of bone marrow or lymph node (identified by H&E/immunohistochemistry or flow cytometry) OR positive myeloid differentiation primary response gene 88 (MYD88-L265P) OR CXCR4WHIM mutation (CXCR4 mutation - warts, hypogammaglobulinemia, infections, myelokathexis) on submitted samples