A considerable proportion of relapsed or refractory large B cells belong to the WHO subtype known as high-grade B-cell lymphoma with rearrangement of MYC and BCL2 and/or BCL6, also known as double-hit lymphoma (DHL).
Double-hit lymphoma (DHL), defined as a dual rearrangement of MYC and BCL2 and/or B-cell CLL/lymphoma 6 (BCL6) genes, is an uncommon subset accounting for 5% to 7% of all diffuse large B-cell lymphomas (DLBCLs), and long-term survivors are rare.
The clinicopathological features of triple hit lymphoma patients were similar to patients with MYC/BCL2 and MYC/BCL6 double hit lymphoma, except that triple hit lymphoma cases were more often CD10 positive compared with MYC/BCL6double hit lymphoma (p < 0.05).
Patients with B cell lymphomas bearing MYC translocation combined with translocation involving other genes, such as BCL2, BCL3, or BCL6, defined as double-hit lymphoma (DHL), have a poor prognosis.
By FISH analysis, 19.6%, 4.6%, 26.1%, and 3.9% cases showed rearrangement at IGH, BCL2, BCL6, and MYC loci, respectively, including three (2.0%) cases of double-hit lymphoma.
Patients with both MYC and BCL2 CNA had similar outcomes to those with classic double hit lymphoma or protein double expression lymphoma (MYC and BCL2/BCL6 coexpression).
We report our experience with 129 cases of double hit lymphoma (DHL), defined as B-cell lymphoma with translocations and/or extra signals involving MYC plus BCL2 and/or BCL6.
Double-hit lymphoma (DHL) has been defined by others as a B-cell lymphoma with MYC/8q24 rearrangement in combination with a translocation involving another gene, such as BCL2, BCL3, or BCL6.