Introduction
Leukemia cutis (LC) is a cutaneous disease caused by the infiltration of neoplastic leukocytes into the skin. The cutaneous manifestations of LC commonly present as patches of homogeneous erythema, papules, and nodules 1. Only one case showing annular erythema as LC due to T-cell acute lymphocytic leukemia (T-ALL) has been reported to date 2. Furthermore, there has been no case showing annular erythema as LC due to B-cell ALL (B-ALL).
Blinatumomab is an antibody drug that mediates the formation of a synapse between T-cells presenting the CD3 antigen and tumor cells presenting the CD19 antigen, resulting in the redirected lysis of CD19-positive B-ALL cells 3. A phase 2 clinical trial showed that the number of neoplastic leukocytes (tumor cells) decreased below the detection limit within a few days and this effect persisted during the period of blinatumomab treatment 3. This trial concomitantly demonstrated that the number of cytotoxic T-cells rapidly decreased within 1 day after the administration of blinatumomab and recovered above the base number within 1 week, the so-called redistribution phenomenon 3. Although immune-modulating drugs, such as blinatumomab, potentially affect the cutaneous manifestations of LC through cytotoxic T-cells, limited information is currently available.
We herein report a case of B-ALL-induced LC with the annular appearance of multiple erythema potentially modified by blinatumomab.