Sequential diffuse large B-cell lymphoma after peripheral T-cell lymphoma not otherwise specified: a case report and review of literature

Objective To investigate the diagnosis and treatment of sequential diffuse large B-cell lymphoma (DLBCL) after peripheral T-cell lymphoma (PTCL). Methods A case with sequential DLBCL after PTCL was reported, and the characteristics and responses of this case were analyzed. The previous literature was reviewed in order to explain the mechanism and prognosis of such type of disease. Results This patient was diagnosed as PTCL not otherwise specified (PTCL-NOS) definitely, but after a period of treatment, DLBCL was developed as a second tumor. The characteristics and onset interval were just similar to those described in the literature, in which the mechanisms were mentioned as common effects of tumor cell, microenviroment and therapies. This patient got effects through the initial treatment, but considering the poor outcome by former researchers, the prognosis needed to be closely followed up. Conclusion Sequential development of EBV-unrelated DLBCL after PTCL-NOS is very rare, and the mechanism, therapy and prognosis need further investigation. Key words: Peripheral T-cell lymphoma, not otherwise specified; Lymphoma, large cell, diffuse; EB virus