Other iatrogenic immunodeficiency lymphoproliferative disorder induced by corticosteroid used for an autoimmune disorder.

Other iatrogenic immunodeficiency lymphoproliferative disorders (oii-LPD) are defined as lymphoid proliferations or lymphomas that occur in patients taking immunosuppressive agents (ISA) for autoimmune disorders (AID). Although methotrexate and tumor necrosis factor-alpha inhibitors cause oii-LPD, the association between corticosteroids and lymphomagenesis remains unknown. Herein, we present the case of a 51-year-old woman with oii-LPD caused by corticosteroid use for autoimmune hemolytic anemia (AIHA). The diagnosis of AIHA was made in May 2016, and AIHA had been well-controlled for 5 years with oral prednisolone (PSL). During a regular follow-up visit in March 2022, an abnormal increase in atypical lymphoid cells in the peripheral blood was found. The bone marrow biopsy specimens showed local aggregations of large cells that were identified as lymphoplasmacytic cells and plasma cells, and that were positive for cluster of differentiation (CD)19 and CD20, with apparent nucleoli among the diffuse infiltration of atypical small lymphocytes. The large cells were partially positive for the Epstein-Barr encoding region