Pseudoprogression of extramedullary lesions during elranatamab therapy in relapsed or refractory multiple myeloma

This case report details a 67-year-old woman with multiple myeloma who experienced pseudoprogression during elranatamab therapy. Initial tumor enlargement and ocular symptoms were managed effectively with dexamethasone. Biopsy and declining M-protein levels confirmed immune-mediated infiltration rather than actual disease progression. The patient achieved a very good partial response, emphasizing the clinical need to distinguish pseudoprogression from true treatment failure.