bcl-2 protein expression and correlation with the interchromosomal 14;18 translocation in cutaneous lymphomas and pseudolymphomas.
The interchromosomal 14;18 translocation occurs in approximately 70-80% of follicular lymphomas and in a lower proportion of high-grade non-Hodgkin lymphomas of the lymph nodes. This translocation results in the fusion of the bcl-2 oncogene on chromosome 18 with immunoglobulin heavy chain genes on chromosome 14, and in the expression of higher amounts of normal bcl-2 protein. We studied bcl-2 expression in biopsies of 108 patients with benign and malignant cutaneous lymphoproliferative diseases (B-cell lymphoma, primary cutaneous, 42; secondary cutaneous, 21; primary cutaneous T-cell lymphoma, 21; B-cell pseudolymphoma, 24), using a monoclonal anti-bcl-2 antibody on paraffin-embedded tissue sections, bcl-2 protein was detected immunohistochemically in 16 of 63 cases of cutaneous B-cell lymphoma, whereas cutaneous T-cell lymphomas and B-cell pseudolymphomas were negative. The proportion of bcl-2 protein expression was significantly higher in secondary (11/21) than in primary cutaneous B-cell lymphomas (5/42; chi 2 test, p < 0.001). Biopsies from 25 of these patients (B-cell lymphoma, 22; B-cell pseudolymphoma, three) were analyzed previously on the molecular level for the t(14;18), using polymerase chain reaction amplification of DNA obtained from paraffin-embedded sections. In four of 11 cases of bcl-2 protein-positive B-cell lymphoma (primary, one; secondary, three) the t(14;18) was detected by polymerase chain reaction. All other cases of B-cell lymphoma, including seven cases where bcl-2 protein was detected by immunohistology, and B-cell pseudolymphoma were negative. These results demonstrate: 1) bcl-2 protein is expressed in a small portion of cutaneous B-cell lymphomas; 2) bcl-2 protein expression is significantly more frequent in secondary than in primary cutaneous B-cell lymphoma; 3) only approximately one-third of cases expressing the bcl-2 protein are characterized also by the t(14;18). bcl-2 protein expression might indicate that the cutaneous manifestation of the lymphoma represents a secondary spread from a node-based lymphoma.
Cerroni
L
L
Department of Dermatology, University of Graz, Austria.
Volkenandt
M
M
Rieger
E
E
Soyer
H P
HP
Kerl
H
H
D015139:Blotting, Southern; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000737:chemistry* / Q000235:genetics*; D016393:Lymphoma, B-Cell / Q000737:chemistry* / Q000235:genetics*; D016410:Lymphoma, T-Cell, Cutaneous / Q000737:chemistry* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2; D012878:Skin Neoplasms / Q000737:chemistry* / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*
D004273:DNA, Neoplasm; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2