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Absence of the t(14;18) chromosomal translocation in primary cutaneous B‐cell lymphoma
Author(s) -
Child F.J.,
RussellJones R.,
Woolford A.J.,
Calonje E.,
Photiou A.,
Orchard G.,
Whittaker S.J.
Publication year - 2001
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1046/j.1365-2133.2001.04128.x
Subject(s) - chromosomal translocation , biology , follicular lymphoma , lymphoma , pathology , b cell , immunoglobulin heavy chain , immunostaining , microbiology and biotechnology , antibody , immunohistochemistry , gene , immunology , medicine , genetics
Background The t(14;18)(q32;q21) chromosomal translocation is found in the majority of nodal follicular lymphomas and in a lower percentage of systemic high‐grade diffuse large B‐cell lymphomas. The translocation results in the juxtaposition of the bcl ‐2 gene on chromosome 18 with the immunoglobulin heavy chain joining region on chromosome 14. Bcl‐2 protein prevents apoptosis and the translocation leads to overexpression of a functionally normal Bcl‐2 protein that prevents apoptosis of neoplastic cells. Objectives The purpose of our study was to analyse cases of primary cutaneous B‐cell lymphoma (PCBCL) for the presence of the t(14;18) translocation and to correlate the results with Bcl‐2 expression and histological subtype. Methods Forty‐four cutaneous B‐cell lymphoid proliferations (36 PCBCL, four follicular B‐cell lymphomas with cutaneous presentation and four reactive B‐cell infiltrates) were analysed by polymerase chain reaction amplification and polyacrylamide gel electrophoresis using consensus primers for the joining region on the immunoglobulin heavy chain gene in combination with either a primer for the major breakpoint region (MBR) or the minor cluster region (mcr) on chromosome 18. Results None of 36 PCBCL analysed demonstrated a t(14;18) translocation; however, three of four systemic follicular B‐cell lymphomas presenting in the skin were found to have a translocation in the MBR, which was confirmed by sequence analysis. Correlation with Bcl‐2 immunostaining showed that of seven patients with high‐grade cutaneous diffuse large B‐cell lymphoma, four were Bcl‐2 positive but had no evidence of a t(14;18) translocation. In the five cases classified as primary cutaneous follicle centre cell lymphoma, the neoplastic cells within the germinal centres failed to express Bcl‐2. However, Bcl‐2‐positive neoplastic cells were present in all four cases of systemic follicular lymphoma, including the case that did not show a t(14;18) translocation. In all cases of marginal zone lymphoma the marginal zone lymphocytes were Bcl‐2 positive. Conclusions These findings indicate that the t(14;18) translocation does not occur in PCBCL, which suggests the involvement of different pathogenetic mechanisms compared with their nodal counterparts. Furthermore, the detection of a t(14;18) translocation in cutaneous B‐cell lymphoma should suggest the presence of systemic disease, which underlies the need for exhaustive staging procedures.