Distribution of NPM1-ALK and X-ALK fusion transcripts in paediatric anaplastic large cell lymphoma: a molecular-histological correlation..     ///    "Reverse transcription polymerase chain reaction detected NPM1-ALK in 58 tumours, all showing nuclear and cytoplasmic ALK staining. "    ///    "Reverse transcription polymerase chain reaction detected NPM1-ALK in 58 tumours, all showing nuclear and cytoplasmic ALK staining."    ///    Almost 90% of paediatric ALK-positive ALCLs express NPM1-ALK. 