Reverse transcription-polymerase chain reaction (RT-PCR) assays were optimized to detect WWTR1-CAMTA1 and YAP1-TFE3 fusion transcripts in FFPE tissue and transcription factor E3 (TFE3) protein accumulation was examined by immunohistochemistry (IHC).     ///    "Fourteen of 18 informative cases were positive for WWTR1-CAMTA1 fusion transcripts, four of which showed higher-grade cytological features termed by some as 'malignant EHE'. "    ///    Subsets have been characterized previously by translocations resulting in either WWTR1-CAMTA1 or YAP1-TFE3 fusion.     ///    This study confirms the high incidence of WWTR1-CAMTA1 and YAP1-TFE3 rearrangements in EHE and indicates that the staining pattern for TFE3 IHC is critical for specificity..     ///    Molecular characterization of epithelioid haemangioendotheliomas identifies novel WWTR1-CAMTA1 fusion variants..     ///    three with patchy staining showed WWTR1-CAMTA1 fusion. 