MED12 and leiomyosarcoma: These latter cases suggest a rare but existing leiomyoma - STUMP - leiomyosarcoma sequence likely depending on the occurrence of further genetic alterations in addition to the driver mutation of MED12. In contrast, neither STUMP nor uterine leiomyosarcomas with HMGA2 alterations akin to those seen in UL have been reported so far.