Biclonal composite lymphoma. A multiparameter flow cytometric analysis
R E Duque1, E T Everett, J Iturraspe
1Department of Pathology, Norwood Clinic Inc, Birmingham, Ala 35234.
Insights
Multiparameter flow cytometry identified a rare biclonal lymphoma composed of two distinct cell populations. This analysis accurately predicted the histologic subtypes of small lymphocytic and diffuse large-cell lymphomas.
Area of Science:
- Hematology
- Oncology
- Immunology
Background:
- Biclonal lymphomas are rare lymphoid malignancies characterized by the presence of two distinct neoplastic cell populations.
- Accurate diagnosis and subtyping are crucial for appropriate treatment and patient management.
Observation:
- Multiparameter flow cytometry was utilized to analyze a case presenting with features suggestive of a composite lymphoma.
- Analysis of cell surface immunophenotype, cell size (forward light scatter), and DNA content revealed two distinct cell populations.
Findings:
- Small, kappa-positive cells coexpressed CD5, were diploid, and had a low synthetic fraction, predicting a small lymphocytic lymphoma.
- Large, lambda-positive cells were hyperdiploid to tetraploid with a high synthetic fraction, predicting a diffuse large-cell lymphoma.
- Histologic examination confirmed both predicted lymphoma subtypes.
Implications:
- Multiparameter flow cytometry is a powerful tool for characterizing complex hematologic malignancies like biclonal lymphomas.
- This technique allows for precise identification of distinct neoplastic clones, aiding in accurate histologic subtyping and potentially guiding therapeutic strategies.
- The findings highlight the utility of flow cytometry in distinguishing between different lymphoma subtypes within a single composite neoplasm.
Abstract:
A case of composite, biclonal lymphoma detected and characterized by multiparameter flow cytometric analysis is presented. Analysis of cell surface immunophenotype and cell size, as assessed by forward light scatter, revealed that two populations of cells were present. The small cells were monoclonal kappa-positive cells admixed with reactive T and B cells. The large cells reacted solely with anti-lambda antibodies. Dual-color and dual-parameter (surface vs DNA) analysis further showed that the small, kappa-positive cells coexpressed CD5 and were diploid, with an estimated synthetic (S) fraction of 2.2%. The predicted histologic pattern was malignant lymphoma, small lymphocytic. In contrast, the large lambda-positive cells were both hyperdiploid and tetraploid with an estimated S fraction of 18%. On the basis of this multiparametric analysis, the predicted histologic pattern for the latter component was malignant lymphoma, diffuse large-cell type. Subsequent histologic examination confirmed the predicted pattern in both cases.
