A 70-yr-old woman was hospitalized with a history of dry cough. Bronchial endoscopy and transbronchial lung biopsy were performed. However, the findings of histopathology and immunohistochemistry were not sufficient to decide whether the lesion was benign or malignant, because of the presence of crush artifacts in the biopsy specimens. We performed B-cell clonality studies using BIOMED-2 multiplex PCR (InVivoScribe Technologies, USA) to detect clonal rearrangements in the immunoglobulin gene. The results of multiplex PCR showed clonal rearrangements of both kappa and lambda immunoglobulin light chain genes. The findings of immunochemistry revealed that the lesion expressed lambda light chain, but not kappa light chain. Based on the clinical, pathologic, and molecular findings, this case was diagnosed as pulmonary MALT lymphoma. We report the first case in Korea of lambda-expressing MALT lymphoma that is shown to have dual clonal rearrangements of kappa and lambda immunoglobulin light chain gene by multiplex PCR.
Aged ; Female ; *Gene Rearrangement, B-Lymphocyte, Light Chain ; Humans ; Immunoglobulin kappa-Chains/*genetics ; Immunoglobulin lambda-Chains/*genetics ; Lymphoma, B-Cell, Marginal Zone/*diagnosis/genetics/pathology ; Polymerase Chain Reaction

OBJECTIVETo study the expression of immunoglobulin light chain kappa and lambda (Igkappa and Iglambda) in gastric carcinoma cell and their co-expression.

METHODSIgkappa and Iglambda of 22 human gastric carcinoma specimens embedded in paraffin were monitored through immunohistochemical method-LSAB method.

RESULTSAmong 22 gastric carcinoma specimens, both Igkappa and Iglambda were positive in 17 (77.3%), only Igkappa was positive in 2 (9.1%), only Iglambda was positive in 1 (4.5%), both Igkappa and Iglambda negative in 2 (9.1%). The expression of Igkappa and Iglambda in human gastric carcinoma cell showed significant close correlation (chi(2) = 5.49, P < 0.05).

CONCLUSIONCo-expression of immunoglobulin light chain kappa and lambda in gastric carcinoma cell is common, which suggests that the activation mechanism of immunoglobulin gene in gastric carcinoma cell may be different from that in B-lymphocytes. Study on co-expression of immunoglobulin light chain kappa and lambda in gastric carcinoma is promising.

Gene Rearrangement, B-Lymphocyte, Light Chain ; Humans ; Immunoglobulin kappa-Chains ; biosynthesis ; genetics ; Immunoglobulin lambda-Chains ; biosynthesis ; genetics ; Immunohistochemistry ; Stomach Neoplasms ; immunology ; metabolism