This study sponsored by the Lymphoreticular Study Group of the Korean Society of Pathologists was carried out to provide nationwide data about the histopathologic-immunophenotypic features of malignant lymphomas in Korea. Two hundred and ninety Non-Hodgkin's lymphoma (NHL) among 312 malignant lymphomas collected from three representative areas in Korea were histologically reclassified. Two hundred and fifty three cases were immunohistochemically studied. T-cell lymphoma comprised 35.2% of NHL in this study and showed a quite comparable incidence to that of Japan and China, but it was much higher than in Western countries. A very low prevalence rate of the follicular variety (4.0%) and a higher propensity of primary extranodal involvement (60%) are additional characteristics of NHL in Korea. The most common histologic subtype of B cell lymphoma was diffuse large cell type, whereas the most common subtype of T cell lymphoma was diffuse mixed small and large cell type.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Female ; Humans ; Immunophenotyping ; Korea ; Lymphoma, Non-Hodgkin/classification/*immunology/*pathology ; Male ; Middle Aged

Recently immunophenotyping has become a valuable tool in the diagnostic workup of malignant lymphoma. We classified 79 consecutive cases of non-Hodgkin's lymphoma experienced at our hospital during the last two years according to the Working Formulation and immunologically using MT1, UCHL1 and MB2 monoclonal antibodies. The results of this study are as follows: 1) four cases (5.1%) were low grade, 54 cases (68.4%) were intermediate grade, and 21 cases (23.3%) were high grade. The most common subtype was 'diffuse, mixed' type, 2) fifty cases (63.3%) showed T-cell phenotype and 14 cases (17.7%) showed B-cell phenotype. Immunophenotyping was impossible in 15 cases due to either double staining or negative staining. 3) the incidence of extranodal presentation was high (65.8%) and the most common extranodal site was the upper aerodigestive tract (29.1%) followed by the gastrointestinal tract (16.4%), and 4) MT1, UCHL1 and MB2 monoclonal antibodies are valuable markers of T- and B-cells in paraffin embedded tissue, enabling retrospective study. However, because these antibodies are not lineage specific, the results of immunostaining should be interpreted with caution.
Adult ; Aged ; Aged, 80 and over ; Female ; Human ; Immunohistochemistry ; Immunophenotyping ; Lymphoma, Non-Hodgkin/classification/immunology/*pathology ; Male ; Retrospective Studies ; Support, Non-U.S. Gov't ; T-Lymphocytes

OBJECTIVETo describe the relative frequency, morphologic features, immunophenotype and clinical data of different types of B-cell non-Hodgkin lymphoma (B-NHL) and to evaluate the practical application of the 2001 World Health Organization (WHO) classification of lymphoid neoplasms.

METHODS369 documented cases of B-NHL were further subtyped according to the 2001 WHO classification of lymphoid neoplasms, on the basis of hematoxylin and eosin staining, immunohistochemistry and in-situ hybridization techniques.

RESULTSAmongst the 369 cases of B-NHL studied, 353 cases could be further classified into 11 subtypes. Diffuse large B-cell lymphoma, extranodal marginal zone lymphoma and follicular lymphoma were the commonest subtypes, accounting for 51.2% (189 cases), 14.9% (55 cases) and 10.6% (39 cases) of all cases respectively. Tumors in lymph nodes were seen in 158 cases (42.8%) and in extra node in 211 cases (57.2%). B-cell prolymphocytic leukemia and hairy cell leukemia were not identified. When comparing the diagnosis based on morphologic examination alone with the diagnosis based on both morphology and immunophenotype, there was a 80% concordance rate. Immunohistochemical study was helpful in reaching the correct diagnosis in many cases and could improve the overall diagnostic accuracy by about 20%.

CONCLUSIONSAmongst cases of B-NHL, diffuse large B-cell lymphoma is the commonest subtype, followed by MALToma and follicular lymphoma. While morphologic examination forms the basis for lymphoma diagnosis, immunohistochemical study also plays an important role in further subtyping. A combination of both modalities are sufficient for arriving at an accurate diagnosis in most cases of B-NHL, in keeping with the recommendation of the 2001 WHO classification of lymphoid neoplasms.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; CD79 Antigens ; metabolism ; Child ; Female ; Humans ; Immunohistochemistry ; Leukosialin ; metabolism ; Lymphoma, B-Cell ; immunology ; pathology ; Lymphoma, B-Cell, Marginal Zone ; immunology ; pathology ; Lymphoma, Follicular ; immunology ; pathology ; Lymphoma, Large B-Cell, Diffuse ; immunology ; pathology ; Lymphoma, Non-Hodgkin ; classification ; immunology ; pathology ; Male ; Middle Aged ; World Health Organization