Multistep tumorigenesis in peripheral T cell lymphoma

Peripheral T cell lymphomas (PTCL) are classified as mature T cell neoplasms. However, several new findings support the notion that premalignant cells arise in the immature stage of hematopoietic differentiation, and subsequently evolve into full-blown T-lineage tumor cells. Acquisition of ( Ten - Eleven Translocation 2 ) TET2 mutations may be an important event for the establishment of premalignant cells. In PTCL harboring features of follicular helper T cells, tumor-specific G17V RHOA mutations co-occur with premalignant TET2 mutations. The G17V ( ras homolog family member A ) RHOA mutations may play important roles in clonal evolution of premalignant cells into tumor cells. Indeed, multistep tumorigenesis is thought to be essential for pathogenesis of PTCL.