Study Of Morphologic, Immunophenotypic And Genetic Features And Their Diagnostic Significance For Mantle Cell Lymphoma

Study of morphologic, immunophenotypic and genetic features and their diagnostic significance for mantle cell lymphomaSHUI RuohongTutor:professor ZHU XiongzengObjective: To study the morphologic, immunophenotypic and genetic features of mantle cell lymphoma and to elucidate their diagnostic significance for mantle cell lymphoma.Methods: Morphologic studies and immunohistochemical analyses of CD45, CD20, cyclin D1, CD5, CD10, CD23 and bcl-2 were performed on 41 cases of mantle cell lymphoma and 91 cases of other small B-cell lymphomas with paraffin-embedded tissues. Using semi-nested polymerase chain reaction (semi-PCR) and DNA sequencing technique, bcl-1/JH genomic DNA was amplified and sequenced in all above mentioned lymphomas and 20 cases of lymphoid reactive hyperplasia with paraffin-embedded tissues. House-keeping gene β-Actin was used to detect the quality of DNA. Using reverse transcription-polymerase chain reaction (RT-PCR), competitive RT-PCR and DNA sequencing technique, cyclin D1 mRNA expression was detected in 38 cases of nodal mantle cell lymphoma, 58 cases of other nodal small B-cell lymphomas and 20 cases of lymphoid reactive hyperplasia with paraffin-embedded tissues. House-keeping gene PGK was used to detect the quality of RNA.Results: (1) Mantle cell lymphomas and other small B-cell lymphomas had distinct histological architectures and different composed cells. Histologically, 41 cases of mantle cell lymphoma showed three patterns: mantle zone (3 cases), nodular (9 cases), and diffuse (29 cases). Cytologically, they were classified as classic mantle cell lymphomas (36 cases), blastoid variants (4 cases) and monocytoid variant (1 case). (2) In immunohistochemistry mantle cell lymphomas and other small B-cell lymphomas were all positive for CD45 and CD20. Mantle cell lymphomas expressedcyclin D1 (70.7%), CD5 (73.2%), bcl-2 (92.7%) and were negative for CD10 or CD23. Among other small B-cell lymphomas, none was positive for cyclin D1. B-SLLs expressed CD5 (86.7%), CD23 (80.0%) and bcl-2 (93.3%); FLs expressed CD10 (86.1%) and bcl-2 (100%); MZLs expressed bcl-2 (42.9%); MALT-Ls expressed bcl-2 (66.7%). (3) Bcl-1/JH genomic DNA was detected in 25 cases of mantle cell lymphoma by semi-nested PCR in paraffin-embedded tissues. The positive rate of bcl-1/JH genomic DNA was 65.8% in mantle cell lymphomas after exclusion of 3 cases which were negative for both bcl-1/JH genomic DNA and β-Actin. Subsequent sequencing showed that sequences were identical to bcl-1/JH and all the breakpoints on chromosome 11q13 were clusted within 50 nucleotides on either side of the SstⅠ restriction site in bcl-1 MTC. Other small B-cell lymphomas or lymphoid reactive hyperplasia were negtive for bcl-1/JH genomic DNA. (4) Cyclin D1 mRNA was detected in 34 cases of nodal mantle cell lymphoma by RT-PCR in paraffin-embedded tissues. The positive rate of cyclin D1 mRNA was 94.4% in mantle cell lymphomas after exclusion of 2 cases which were negative for both cyclin D1 mRNA and PGK. Cyclin D1 mRNA was not detected in other nodal small B-cell lymphomas or lymphoid reactive hyperplasia, except 1 case of B-SLL. Sequencing analysis showed that sequences were identical to cyclin D1. (5) Cyclin D1 mRNA overexpression was detected in 27 cases of nodal mantle cell lymphoma by competitive RT-PCR in paraffin-embedded tissues. The positive rate of cyclin D1 mRNA overexpression was 75.0% in mantle cell lymphomas after exclusion of 2 cases which were negative for both cyclin D1 mRNA and PGK. Cyclin D1 mRNA overexpression was not detected in other nodal small B-cell lymphomas or lymphoid reactive hyperplasia.Conclusions: (1) Mantle cell lymphomas and other small B-cell lymphomas have distinct histological architectures and different composed cells, both of which can be used in the diagnosis and differential diagnosis of mantle cell lymphoma. (2) Mantle cell lymphomas and other small B-cell lymphomas have different immunophenotypes. Immunohistochemical detection of cyclin D1, CD5, CD10, CD23 in paraffin-...