Immunocytochemical p63 expression discriminates between primary cutaneous follicle centre cell and diffuse large B-cell lymphoma-leg type, and is of the TAp63 isoform

Abstract

INTRODUCTION: The p63 gene shares structural and functional homologies with the p53 family of transcriptional activators, but differs in exhibiting a consistent expression pattern in normal tissues. Although p63 is rarely mutated in malignancy studies of primary human tumours and cell lines suggest p63 may promote tumour development. In non-Hodgkin's nodal lymphoma, TAp63 expression in follicular lymphoma (54%) and diffuse large B-cell lymphoma (34%) has been described and correlated with proliferative index. In this study, we analysed a series of primary cutaneous B-cell lymphomas for immunohistochemical expression of p63.
METHODS: 30 cases of diffuse large B-cell lymphoma leg type (pcDLBCLL) and 34 cases follicle centre cell lymphoma (pcFCCL) were stained using a generic antibody to p63, and a subset of these with an antibody specific for delta-Np63 isoform.
RESULTS: Results indicate a significant difference between pcDLBCLL (21/30) & pcFCCL(4/34) in p63 expression (p=0.000); expression correlated strongly with proliferation rate as assessed by Ki-67 (p= 0.015). None of the p63(+) cases tested expressed delta-Np63 isoform suggesting expression is of the TAP isoform.
CONCLUSION: Functional studies are required to clarify the significance of p63 overexpression in primary cutaneous B-cell lymphoma. This article is protected by copyright. All rights reserved.