Case study: Acute plasmoblastic leukemia presentation following effective haploidentical hematopoietic stem cell transplantation therapy.

Plasma cell leukemia is a rare and aggressive malignancy characterized by monoclonal gammopathy and the presence of circulating plasma cells in the peripheral blood. Therapeutic strategies for plasma cell leukemia remain undefined, with treatments primarily borrowed from those used in multiple myeloma. The first-line treatment typically involves a combination of a proteasome inhibitor, an immunomodulatory agent, steroids, and/or anthracyclines and alkylators within an intensive chemotherapy regimen. Following this, consolidation with autologous hematopoietic stem cell transplantation is offered to eligible patients, followed by maintenance therapy. For patients ineligible for autologous hematopoietic stem cell transplantation, allogeneic hematopoietic stem cell transplantation is considered a viable alternative. Given the challenges in securing a fully human leukocyte antigen-matched donor, haploidentical hematopoietic stem cell transplantation serves as a potential salvage therapy, as demonstrated in the clinical case presented. This article presents the case of a female patient in her 50s diagnosed with plasma cell leukemia who, following unsuccessful autologous hematopoietic stem cell mobilization, underwent haploidentical hematopoietic stem cell transplantation from her son, resulting in complete donor chimerism and a favorable response.