BCL6 and high grade B-cell lymphoma: Differentiating DLBCL NOS from other LBCL types, particularly from DLBCL/high-grade B cell lymphomas (HGBL) with MYC/BCL2 rearrangements (double hit), typically involves morphological assessment, immunophenotyping, and fluorescence in situ hybridization (FISH) for BCL2, BCL6, and MYC rearrangements [9].