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Updated: Aug 10, 2026
Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
Published on: November 26, 2018
Immunophenotype analysis of B-CLL lymphoma and immunocytoma
U Martinsson1, C Sundström, B Glimelius
1Department of Oncology, University of Uppsala, Akademiska sjukhuset, Sweden.
Insights
Distinguishing B-cell chronic lymphocytic leukemia (B-CLL) from immunocytoma (IC) is challenging. Immunophenotyping using the FMC7 antibody significantly aids differentiation, with most B-CLL cases being FMC7- and most IC cases being FMC7+.
Area of Science:
- Hematology
- Immunology
- Oncology
Background:
- Morphological assessment alone can be insufficient for differentiating B-cell chronic lymphocytic leukemia (B-CLL) from immunocytoma (IC).
- Accurate diagnosis is crucial for appropriate patient management and treatment strategies.
Purpose of the Study:
- To improve the diagnostic distinction between B-CLL and IC using immunophenotyping.
- To evaluate the utility of specific monoclonal antibodies in differentiating these lymphoid malignancies.
Main Methods:
- Frozen sections of lymph nodes and biopsied tissues from 14 B-CLL and 16 IC cases were analyzed.
- A panel of 13 B cell-associated and 2 T cell-associated monoclonal antibodies was employed for immunophenotyping.
Main Results:
- A statistically significant difference was observed in FMC7 expression: 13/14 B-CLL cases were FMC7-negative, while 14/16 IC cases were FMC7-positive (p < 0.001).
- Two IC cases, classified as lymphoplasmacytic, showed FMC7 negativity, potentially due to increased cellular differentiation resembling plasma cells.
- A significant difference in CD38 (Leu-17) expression was also noted (B-CLL: 3/14, IC: 10/16 positive; p < 0.01).
Conclusions:
- Immunophenotyping, particularly using the FMC7 antibody, is a valuable tool for differentiating B-CLL from IC.
- FMC7 negativity is highly characteristic of B-CLL, while FMC7 positivity is more common in IC.
- CD38 expression may also contribute to the differential diagnosis.
Abstract:
The differential diagnosis between lymphocytic lymphoma of the B-CLL type and immunocytoma (IC) can be difficult when it is based only upon morphological criteria. With the aim of improving the distinction between these subgroups, frozen sections of lymph nodes or other biopsied tissues from 14 cases of B-CLL and 16 cases of IC were investigated according to immunophenotype. A panel of 13 B cell-associated and 2 T cell-associated monoclonal antibodies was used. All but one of the B-CLL cases were FMC7-, while 14/16 IC cases were FMC7+ (p less than 0.001). The two negative IC cases were both of the lymphoplasmacytic type, claimed to be "more differentiated" than the lymphoplasmacytoid type. We suggest that the cells in these cases are mature enough to have lost their FMC7 positivity, similar to plasma cells. There was also a statistically significant (p less than 0.01) difference, although not as pronounced, for the anti-CD38 antibody (Leu-17, B-CLL: 3/14, IC: 10/16 positive). No significant difference in expression of determinants was found for any of the other antibodies.
