Synchronous Occurrence of Acute Myeloid Leukemia and Multiple Myeloma: A Case Report and Literature Review.

Multiple myeloma (MM) and acute myeloid leukemia (AML) are malignant clonal disorders with divergent lineages. It is extremely uncommon for both conditions to be diagnosed simultaneously in a patient. This case report examines the uncommon occurrence of AML alongside MM in a 60-year-old male patient. The diagnosis of AML was based on the World Health Organization benchmark, and the patient was categorized as having AML with myelodysplastic defining molecular changes. The patient completed the first cycle of induction chemotherapy with daunorubicin, cytarabine, and gemtuzumab ozogamicin but had a poor response, indicating refractory disease. A bone marrow aspiration following treatment revealed 30% blasts and 11% plasma cells. These plasma cells were CD138 positive and were not present at the time of diagnosis. Additionally, M-protein was detected in the blood. Intermediate chemotherapy with venetoclax and azacitidine was considered, as the patient was not fit for the combination of fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin. Furthermore, the myeloma was not treated as he was not fit for any intensive chemotherapy. The patient's disease was refractory despite four cycles of venetoclax and azacitidine, as evident by residual blasts of 32% in the bone marrow.