Vivero M, et al. - Eight metaplastic thymomas were recovered from two institutions’ archives over a 21-year period in order to report for the first time recurrent translocation events in metaplastic thymomas involving the Yes Associated Protein 1 (YAP1) and Mastermind Like Transcriptional Coactivator 2 (MAML2) genes. At 1–22 years of follow-up, each case exhibited specific histologic peculiarities of metaplastic thymoma and showed no local recurrence or distant metastatic disease. Six of eight cases were successfully sequenced, all designating YAP1-MAML2 fusions and the fusions were identified via DNA sequencing in four cases and through RNA sequencing in two. Two different products were recognized, ie, 5′ YAP1 exon 1 fused to 3′ MAML2 exons 2–5 or 5′ YAP1 exons 1–5 fused to 3′ MAML2 exons 2–5. All cases underwent allele-specific real-time polymerase chain reaction and no GTF2I L424H mutations was shown. Hence, metaplastic thymoma is a different, clinically inactive thymic epithelial neoplasm identified by YAP1-MAML2 fusion and lacking the GTF2I mutations observed in Type A and AB thymomas.