PLoS One. 2020 Nov 12;15(11):e0241634. doi: 10.1371/journal.pone.0241634. eCollection 2020.
AIM: Lymphoplasmacytic lymphoma (LPL) is an indolent mature B-cell-neoplasm with involvement of the bone marrow. At least 90% of LPLs carry MYD88-L265P mutation and some of them (~10%) transform into diffuse large B-cell-lymphoma (DLBCL).
MATERIAL AND METHODS: Over the past 15 years we have collected 7 cases where the both LPL and DLBCL were diagnosed in the same patient. Clinical records, analytical data and histopathological specimens were reviewed. FISH studies on paraffin-embedded tissue for MYC, BCL2 and BCL6 genes were performed, as well as MYD88-L265P mutation and IGH rearrangement analysis by PCR. A mutational study was done by massive next generation sequencing (NGS).
RESULTS: There were 4 women and 3 men between 36-91 years of age. Diagnoses were made simultaneously in 4 patients. In two cases the LPL appeared before the DLBCL and in the remaining case the high-grade component was discovered 5 years before the LPL. In 6 cases both samples shared the MYD88-L265P mutation. IGH rearrangement analysis showed overlapping features in two of 6 cases tested. Mutational study was evaluable in three cases for both samples showing shared and divergent mutations.
CONCLUSIONS: These data suggest different mechanisms of DLBCL development in LPL patients.