To identify cells carrying the t(2;5) translocation, we used immunohistochemistry to detect the ALK-encoded p80 protein and in situ hybridization for the specific detection of NPM-ALK transcripts.     ///     The t(2;5) generates a chimeric NPM-ALK transcript encoded by the nucleophosmin NPM gene fused to the anaplastic lymphoma kinase gene ALK.     ///    Both p80 protein and NPM-ALK transcripts were expressed by anaplastic or large CD30+ lymphoma cells with positive NPM-ALK amplification.     ///    Using a reverse transcriptase nested polymerase chain reaction assay we have detected NPM-ALK transcripts within CD30+ primary cutaneous lymphoma and lymphomatoid papulosis (LP). 