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Updated: Aug 8, 2026
Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
Published on: November 26, 2018
Immunophenotypic and molecular analysis of a case of lymphocytic interstitial pneumonia
B Kawabuchi1, S Tsuchiya, K Nakagawa
1Department of Pathology, University of Tokyo, Japan.
Insights
This study investigated lymphocytic interstitial pneumonia using immunophenotypic and molecular methods. Findings indicated a reactive process, not malignant lymphoma, due to uniform lymphocyte distribution and unrearranged immunoglobulin genes.
Area of Science:
- Pulmonary Pathology
- Immunology
- Molecular Diagnostics
Background:
- Lymphocytic interstitial pneumonia (LIP) diagnosis can be challenging, often requiring advanced techniques to differentiate reactive processes from neoplastic conditions like lymphoma.
- This case highlights the importance of immunophenotypic and molecular analyses in resolving diagnostic ambiguity in pulmonary interstitial diseases.
Observation:
- A 43-year-old female presented with a lung lesion initially suspected as malignant lymphoma.
- Histological examination revealed thickened interstitia with significant small lymphocyte infiltration and germinal centers.
- Immunostaining showed even distribution of immunoglobulin kappa and lambda-bearing cells, suggesting a polyclonal response.
Findings:
- Immunoglobulin gene analysis confirmed unrearranged germ-line DNA, lacking evidence of clonal rearrangement.
- The combination of even immunoglobulin distribution and unrearranged DNA strongly supports a reactive, non-neoplastic etiology for the observed lung lesion.
Implications:
- Accurate differentiation between reactive LIP and pulmonary lymphoma is crucial for appropriate patient management and treatment.
- These findings underscore the utility of integrated immunophenotypic and molecular approaches in diagnosing complex pulmonary lesions.
- This case contributes to the understanding of LIP pathogenesis and diagnostic criteria.
Abstract:
A case of lymphocytic interstitial pneumonia was studied immunophenotypically and with molecular methods in order to clarify its lymphocytic clonality. The patient, a 43 year old Japanese female, underwent lobectomy for a suspected malignant lymphoma as no clear diagnosis could be made from the biopsy specimen. An ill-demarcated, yellowish and elastic firm lesion measuring 60 x 35 x 20 mm in size was located in the peripheral part of the middle lobe of the right lung. Histologically, the alveolar, peribronchial-vascular and subpleural interstitia within the lesion were thickened markedly with severe cellular infiltration largely composed of small lymphocytes with germinal centers. Immunostaining revealed immunoglobulin (Ig) kappa and Ig lambda-bearing cells to be evenly distributed, suggestive of polyspecificity. Immunoglobulin gene analysis further demonstrated the unrearranged germ-line DNA but no rearranged band. These results strongly indicated a reactive process rather than a neoplastic nature for the lesion.
