Waldenstrom's macroglobulinemia (WM) is an uncommon B-cell chronic lymphoproliferative disorder (CLPD). Lymphoplasmacytic lymphoma is thought to correspond to most cases of WM, but the range of pathologic features of WM is not well defined. We studied the morphologic and phenotypic features of the bone marrow (BM) and/or peripheral blood (PB) of 26 cases of WM to address this issue. WM was defined by an IgM serum spike of 3.0 g/dl or more, coupled with a clonal lymphocyte population in the BM or PB. In all 26 cases, clinical data were collected, and BM and/or PB specimens were analyzed morphologically and phenotypically, using flow cytometry (FC) +/- paraffin section immunohistochemistry (PIH). There were 18 men and 8 women, with a median age of 64 years. Lymphoma was identified morphologically in 11/21 PB smears (52%), 18/19 BM aspirates (95%), and 24/25 BM biopsies (95%), and by FC in all the PB and BM specimens tested, including 4 PB and 1 BM specimen that were negative by morphology. The neoplastic cells were composed of a cytologie spectrum of small lymphocytes (SL), plasmacytoid lymphocytes (PL), and plasma cells (PC). BM biopsy involvement ranged from <10%90%, and showed 4 histologie patterns: nodular (75%), interstitial (75%), paratrabecular (42%), and diffuse (4%). Several cytologie variants, including monocytoid (n=2), signetring cell (n=2), and hairy cell leukemia (HCL)-like (n=l) were also seen. By FC, all cases showed light chain restriction and expressed CD19 and CD20. Most cases (n=16) lacked expression of CDS, CD23, and CD10. However, variants such as CD5+, CD23-, CD10-(n=3), CD5+, CD23+, CD10- (n=l), and CDS-, CD23-, CD10+ (n=2), mimicking mantle cell lymphoma (MCL), B-cell chronic lymphocytic leukemia (CLL), and follicular lymphoma (FL), respectively, were also identified. By PIH, the neoplastic cells stained more intensely with CD79a than with CD20, rarely showed weak, focal expression of CD23 (n=l), CD10 (n=3), or DBA.44 (n=l), and were uniformly negative for cyclin Dl. At last follow-up (median 25 months), 18/23 patients were alive. Median duration of survival was 94 months. One tumor transformed to large cell lymphoma; the patient died 5 months later. The defining feature of WM is a cytologie spectrum of SL, PL, and PC. However, since the morphologic and/or phenotypic features may overlap with other CLPD's such as MCL, CLL, FL, marginal zone lymphoma, and HCL, it may not be prudent to diagnose WM based solely on a BM or PB specimen without a classic clinical/laboratory picture.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - Dec 1 2000|
ASJC Scopus subject areas
- Cell Biology