Waldenstrom macroglobulinemia and simultaneous intravascular large B-cell lymphoma: Rare transformation or unhappy coincidence?

Intravascular large B-cell lymphoma (IVLBCL) is a rare, aggressive neoplasm in which lymphoma cells proliferate within the lumens of small blood vessels. 1 Swerdlow S.H. Campo E. Harris N.L. et al. WHO classification of tumours of haematopoietic and lymphoid tissues. Revised. 4th ed. IARC, 2017: 317 Google Scholar Diagnosis can be challenging given heterogeneous and non-specific symptoms such as fever, neurological changes, hypoxia, and skin rashes and the frequent absence of lymphoma cells on peripheral blood smear. 2 Ponzoni M. Campo E. Nakamura S. Intravascular large B-cell lymphoma: a chameleon with multiple faces and many masks. Blood. 2018; 132: 1561-1567https://doi.org/10.1182/blood-2017-04-737445 Crossref PubMed Scopus (86) Google Scholar Concurrent biopsy of 3 random sites of skin and subcutaneous tissue may improve diagnostic sensitivity for IVLBCL compared to biopsy of a single site. 3 Matsue K. Abe Y. Kitadate A. et al. Sensitivity and specificity of incisional random skin biopsy for diagnosis of intravascular large B-cell lymphoma. Blood. 2019; 133: 1257-1259https://doi.org/10.1182/blood-2018-11-887570 Crossref PubMed Scopus (39) Google Scholar Waldenstrom macroglobulinemia (WM) is a distinct B cell-derived malignancy, characterized by secretion of monotypic IgM and free light chains by lymphoplasmacytic lymphoma cells in the bone marrow and sometimes the peripheral blood. 4 Owen R.G. Treon S.P. Al-Katib A. et al. Clinicopathological definition of Waldenstrom's macroglobulinemia: consensus panel recommendations from the Second International Workshop on Waldenstrom's Macroglobulinemia. Semin Oncol. 2003; 30: 110-115https://doi.org/10.1053/sonc.2003.50082 Crossref PubMed Scopus (729) Google Scholar Histologic transformation of WM to diffuse large B-cell lymphoma (DLBCL) has been described, with 1 series suggesting a transformation rate of 2.4% at ten years following WM diagnosis, 5 Castillo J.J. Gustine J. Meid K. Dubeau T. Hunter Z.R. Treon S.P. Histological transformation to diffuse large B-cell lymphoma in patients with Waldenström macroglobulinemia. Am J Hematol. 2016; 91: 1032-1035https://doi.org/10.1002/ajh.24477 Crossref PubMed Scopus (38) Google Scholar and another indicating that up to 13% of patients with WM may eventually be diagnosed with DLBCL. 6 Lin P. Mansoor A. Bueso-Ramos C. Hao S. Lai R. Medeiros L.J. Diffuse large B-cell lymphoma occurring in patients with lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Clinicopathologic features of 12 cases. Am J Clin Pathol. 2003; 120: 246-253https://doi.org/10.1309/R01V-XG46-MFCD-VNHL Crossref PubMed Google Scholar Transformed WM frequently involves extranodal sites, including the bone marrow, bone, spleen, liver, pleura, gastrointestinal and genitourinary tracts, skin, and central nervous system. 5 Castillo J.J. Gustine J. Meid K. Dubeau T. Hunter Z.R. Treon S.P. Histological transformation to diffuse large B-cell lymphoma in patients with Waldenström macroglobulinemia. Am J Hematol. 2016; 91: 1032-1035https://doi.org/10.1002/ajh.24477 Crossref PubMed Scopus (38) Google Scholar ,7 Durot E. Tomowiak C. Michallet A.S. et al. Transformed Waldenström macroglobulinaemia: clinical presentation and outcome. A multi-institutional retrospective study of 77 cases from the French Innovative Leukemia Organization (FILO). Br J Haematol. 2017; (179): 439-448https://doi.org/10.1111/bjh.14881 Crossref PubMed Scopus (26) Google Scholar This report presents a case of concurrent and clonally related LPL and IVLBCL, a phenomenon which to our knowledge has not been described previously.