Immunoglobulin and T cell receptor β chain gene rearrangement analysis of ocular adnexal lymphoid neoplasms: Clinical and biologic implications
Receptors, Antigen, T-Cell
We investigated the organization of the immunoglobulin heavy chain (IgH) and the T cell receptor beta chain (T beta) gene loci in 20 ocular adnexal and four extraocular lymphoid neoplasms obtained from 18 patients presenting with an ocular adnexal lymphoid neoplasm. Fifteen ocular adnexal and four extraocular lymphoid neoplasms occurring in 13 patients were classified by morphological examination and immunophenotypic analysis as monoclonal B cell lymphomas. Each one of these 19 lymphoid neoplasms exhibited clonal IgH gene rearrangements upon hybridization of EcoRI- or HindIII-digested DNA to a heavy-chain joining region (JH)-specific DNA probe. The bilateral ocular adnexal monoclonal B cell neoplasms occurring simultaneously in two individuals exhibited identical clonal IgH gene rearrangements, which indicated their derivation from an identical B cell clone. The ocular adnexal and the extraocular monoclonal B cell neoplasms occurring in two of three patients also exhibited identical clonal IgH gene rearrangements, which suggested that they too were derived from an identical B cell clone. Five ocular adnexal lymphoid neoplasms were classified by morphological examination and immunophenotypic analysis as benign, polyclonal pseudolymphomas. Three of these five ocular adnexal lymphoid neoplasms exhibited clonal IgH gene rearrangements, which suggested the presence of monoclonal B cell populations that escaped detection by morphological and immunophenotypic examination. None of the 24 pathological samples exhibited clonal T beta gene rearrangements upon hybridization of EcoRI- or BamHI-digested DNA to a T beta gene DNA probe. The results of these studies demonstrate the value of Southern blot hybridization analysis for clonal IgH and T beta gene rearrangements in the diagnosis, classification, and investigation of extranodal lymphoid neoplasms originating and/or presenting in the ocular adnexa.