Therapy-related B-cell acute lymphoblastic leukemia after treatment for multiple myeloma

This article details four cases of therapy-related B-cell acute lymphoblastic leukemia (t-B-ALL) developing after treatment for multiple myeloma (MM). Patients treated with novel agents and stem cell transplants developed aggressive t-B-ALL within three to seven years. Characterized by pancytopenia and clonal independence from original MM cells, this rare secondary malignancy carries an extremely poor prognosis compared to de novo cases.