these results must be confirmed in prospective studies of patients with uniform staging and therapy to more fully understand the clinical significance of the t(2;5) and its novel chimeric protein, NPM-ALK..     ///    "Multiple techniques including reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of NPM-ALK fusion transcripts, genomic DNA-PCR, RNA in situ hybridization, and fluorescence in situ hybridization (FISH) of metaphase chromosomes and interphase nuclei, and immunohistochemical detection of the 80 kilodalton protein (p80) derived from the NPM-ALK fusion have enabled surveys of normal and lymphoma tissues for evidence of the translocation. "    ///    "In lymphoma, NPM-ALK expression is most often seen in young patients with the monomorphic or small-cell variant of ALCL who present with advanced stage disease and have tumors with a CD30+, T- or null-cell phenotype. "    ///    "NPM-ALK is rarely, if ever, detected in Hodgkin's disease or secondary ALCL. "    ///    A retrospective study has suggested that expression of NPM-ALK is associated with a better overall 5-year survival.     ///    "In addition, expression of NPM-ALK has been found in occasional CD30 negative B-cell lymphomas with diffuse large cell or immunoblastic histology. "    ///    "Although initially found in primary nodal ALCL, recent studies suggest that NPM-ALK expression may occur in lymphoma at extranodal sites, including the skin. "    ///    "it remains controversial, however, whether CD30+ primary cutaneous lymphoma and its benign counterpart, lymphomatoid papulosis (LyP), express NPM-ALK in some cases. "    ///    "This translocation creates a novel fusion protein, NPM-ALK, which has transforming properties in vitro and can cause large-cell lymphoma in vivo when transfected into murine bone marrow. "