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Updated: Aug 8, 2026
Chromosome Preparation From Cultured Cells
Published on: January 28, 2014
Numerical cytogenetic abnormalities of chromosomes 3, 7, and 12 in marginal zone B-cell lymphomas
R K Brynes1, P D Almaguer, K E Leathery
1Division of Pathology, City of Hope National Medical Center, Duarte, CA 91010, USA. rbrynes@smtplink.coh.org
Insights
Trisomy 3 is common in marginal zone B-cell lymphomas (MZBCLs) with monocytoid B-cell features, but rare in primary splenic marginal zone cell lymphomas (SMZCLs). This suggests genetic differences between these related B-cell lymphomas.
Area of Science:
- Hematology
- Oncology
- Cytogenetics
Background:
- Marginal zone B-cell lymphomas (MZBCLs) encompass extranodal (MZBCL-E) and nodal (MZBCL-N) types, often exhibiting monocytoid B-cell morphology.
- Primary splenic marginal zone cell lymphoma (SMZCL) shares some features but is considered distinct.
- Numerical chromosomal abnormalities, particularly trisomy 3, are frequent in non-Hodgkin's lymphomas and have been reported in MZBCLs.
Purpose of the Study:
- To investigate the frequency of trisomy 3 and other numerical chromosomal abnormalities in MZBCLs with monocytoid B-cell features.
- To compare the cytogenetic profile of MZBCL-E and MZBCL-N with monocytoid B-cell morphology to that of primary SMZCL.
- To determine if trisomy 3 can serve as a distinguishing genetic marker between these related lymphoma entities.
Main Methods:
- Retrospective analysis of 36 formalin-fixed, paraffin-embedded tissue blocks from patients with MZBCL-E, MZBCL-N, and SMZCL.
- Fluorescence in situ hybridization (FISH) was employed to detect specific chromosome trisomies (3, 7, and 12).
- Statistical analysis was performed to compare the incidence of trisomies across the different lymphoma subtypes.
Main Results:
- Trisomy 3 was detected in 85% of MZBCL-Es and 50% of MZBCL-Ns with monocytoid B-cell features.
- In contrast, only 18% of SMZCL cases showed trisomy 3.
- Trisomies 7 and 12 were observed less frequently across all studied groups.
Conclusions:
- Trisomy 3 is a prevalent numerical chromosomal abnormality in marginal zone B-cell lymphomas (MZBCLs) exhibiting monocytoid B-cell cytologic features.
- The significantly lower incidence of trisomy 3 in primary splenic marginal zone cell lymphomas (SMZCLs) suggests a distinct genetic basis for this entity.
- These findings support the classification of SMZCL as a separate entity from MZBCLs and highlight trisomy 3 as a potential diagnostic marker.
Abstract:
Monocytoid B-cell lymphoma, low-grade B-cell lymphoma of mucosa-associated lymphoid tissue, and primary splenic marginal zone cell lymphoma (SMZCL) were originally described as distinct clinicopathologic entities. On the basis of morphologic and immunologic similarities, monocytoid B-cell lymphoma and lymphoma of mucosa-associated lymphoid tissue recently have been grouped together as nodal and extranodal types of marginal zone B-cell lymphomas (MZBCLs) in the Revised European-American Classification of Lymphoid Neoplasms. Primary SMZCL, although related, is considered a separate provisional entity. Trisomies 3, 7, and 12 are common in non-Hodgkin's lymphomas. Several recent studies reported that MZBCLs arising in sites of mucosa-associated lymphoid tissue have a high frequency of trisomy 3. To assess whether similar numerical cytogenetic abnormalities are present in MZBCLs with prominent monocytoid B-cell cytologic features, we performed a retrospective study, using formalin-fixed, paraffin-embedded tissue blocks from 36 cases. By use of fluorescence in situ hybridization to detect chromosome trisomies, we identified trisomy 3 in 11 (85%) of 13 extranodal MZBCLs with monocytoid B cells (MZBCL-Es), in 6 (50%) of 12 nodal MZBCLs of monocytoid B-cell type (MZBCL-Ns), but in only 2 (18%) of 11 SMZCLs. Trisomies 7 and 12 were found at lower frequencies. These data suggest that trisomy 3 is a common numerical chromosomal abnormality of MZBCL-Es and MZBCL-Ns with monocytoid B-cell features. Despite similar morphologic and immunophenotypic characteristics, the low incidence of trisomy 3 in the SMZCL cases implies that this process may be genetically distinct.
