Intravascular large B-cell lymphoma secondary to lymphoplasmacytic lymphoma: a case report and review of literature with clonality analysis.

Intravascular large B-cell lymphoma (IVLBCL) can be a fatal malignancy mainly because of difficulty in early detection. Due to the lack of specific clinical manifestations, early detection of IVLBCL remains a challenge, especially in the presence of comorbidities. Lymphoplasmacytic lymphoma (LPL) is an indolent B-cell lymphoma accompanied by monoclonal immunoglobulin M protein in most patients, and known to be associated with high risk of secondary hematological malignancies. Here, we report a patient who developed IVLBCL during treatment for LPL that presented a diagnostic challenge. Rearrangement analysis of the immunoglobulin heavy chain revealed the different clonal origins of two lymphomas, implying a predisposition of LPL to develop unrelated secondary lymphoma. Secondary lymphoma including IVLBCL during the treatment for LPL deserves consideration in order to facilitate early diagnosis and intervention.