Abstract
Discrimination between Waldenström macroglobulinemia (WM) and marginal zone lymphoma (MZL) of the bone marrow (BM) can be difficult due to overlap in clinical, histopathologic, and immunophenotypic characteristics. We determined which characteristics can aid in the differential diagnosis of ‘gray zone’ cases. We compared clinical, histopathologic, immunophenotypic, and molecular features of 222 WM and 65 MZL patients. LASSO regression was employed for variable selection. The most distinguishing clinical features of WM compared to MZL were the presence of the B-symptom weight loss and IgM paraprotein. Histopathological findings were plasmacytoid differentiation, monoclonal plasma cells, and increased mast cells in the BM. Regarding flow cytometry, only CD10 and CD38 were distinguishing markers. Finally, as the expected presence of the MYD88L265P mutation showed to be of great value in the distinction between WM and MZL. Despite the great overlap, WM can often be distinguished from MZL by using a combination of characteristics. These characteristics should be weighed in complex, ‘gray zone’ cases.
Author contributions
KA and MJK designed the study; MJK, MM, and JV provided the data; KA analyzed the data; AZ provided statistical support; KA wrote the manuscript with contributions from all authors, who also interpreted the data, and read, commented on, and approved the final version of the manuscript.
Disclosure statement
The authors declare no significant competing financial, professional, or personal interests that might have influenced the performance or presentation of the work described in this manuscript.
Data availability statement
The data that support the findings of this study are available from the corresponding author, MJK, upon reasonable request.