J Hematol

Journal of Hematology, ISSN 1927-1212 print, 1927-1220 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Hematol and Elmer Press Inc

Journal website https://www.thejh.org

Case Report

Volume 11, Number 6, December 2022, pages 233-239

Bone Involvement as a Primary Rare Manifestation of Waldenstrom Macroglobulinemia: A Case Report and Prevalence in a Nationwide Population-Based Cohort Study

Figures

Figure 1. Sagittal T1-weighted MRI of lumbar and thoracic spine (a) showing multiple vertebral fractures and osteopenia (arrows). Coronal STIR MRI (b) and axial CT image (c) of the hip joints with a suspected malignant process in the left proximal femur and a subcapital fracture (arrows), with accompanying synovitis and accumulation of fluid in the left hip joint. MRI: magnetic resonance imaging; CT: computed tomography.

Figure 2. Lymph node biopsy with diffuse infiltration of small, uniform B-lymphocytes and plasmacytoid cells (a) with strong expression of CD20 (b). Bone marrow infiltration of monoclonal LPL cells (c) expressing CD20 (d). Flow cytometry identifies a distinct clonal population of B cells (CD19⁺, CD20⁺) which are negative for CD5 and CD10 (e). LPL: lymphoplasmacytic lymphoma.

Table

**Table 1.** Clinical Data Characteristics of 2,454 Newly Diagnosed WM/LPL Patients With and Without Bone Involvement
	Patients with bone involvement (n = 43)	Patients without bone involvement (n = 2,411)	P value^a
^aP value by Chi-square and Mann-Whitney U tests. WM: Waldenstrom macroglobulinemia; LPL: lymphoplasmacytic lymphoma; IgM: immunoglobulin M; M: male; F: female.
Age ≥ 70 years, n (%)	26 (60.5)	1,424 (59.1)	0.877
Gender (M/F ratio)	2.6	1.6	0.205
WM/LPL ratio	1.7	4.2	0.003
IgM M component, n (%)	27 (62.8)	1,946 (80.7)	0.003
IgM M component ≥ 20 g/L, n (%)	9 (20.9)	755 (31.3)	0.183
B-symptoms, n (%)	16 (37.2)	466 (19.3)	0.003
Performance status > 1, n (%)	7 (16.2)	213 (8.8)	0.101
Treatment initiated at diagnosis, n (%)	30 (69.8)	906 (37.6)	0.00002