Multiple Myeloma On Top of Chronic Myelogenous Leukemia

The occurrence of multiple myeloma (MM) in patients with chronic myelogenous leukemia (CML) is an extremely rare event. There are only 10 cases reported in literature, with only 5 of them treated with imatinib. The longest was for 65 months.

A 70-year-old Caucasian female presented for follow-up on her chronic myelogenous leukemia (CML). She was diagnosed 8 years prior and had a Philadelphia chromosome positive on FISH and PCR. She had been treated with Imatinib for 72 months and initially responded well, but later developed pancytopenia and hematologic and cytogenetic progression of her CML despite dose adjustments. She was switched to Nilotinib 15 months prior with partial cytogenetic response, and persistence of her pancytopenia. Her symptoms were fatigue and weight loss. She denied bleeding, fever, or back pain. Her physical exam was unremarkable. Her labs showed hemoglobin of 8.5 g/dL, WBC 2.2 K/μL with 48% segmented and platelets count of 30 K/μL.

Bone marrow biopsy and aspirate showed 15–20% clustered monoclonal plasma cells and persistence of CML. Serum IgG was 2248 mg/dL with an IgG Kappa monoclonal peak on serum protein electrophoresis. A skeletal bone survey revealed no lytic lesions. Otherwise her laboratory findings were unremarkable except for a creatinine of 1.39 mg/dL and a β-2-microglobulin of 4.6 mg/L. She was diagnosed with multiple myeloma, and started on chemotherapy with bortezomib, liposomal doxorubicin, and dexamethasone. Nilotinib was held. After 4 cycles of chemotherapy, her repeat bone marrow biopsy showed partial remission of MM, and persistence of CML. Her blood counts are improving.

A PubMed review of literature shows 10 reported cases of MM occurrence in patients with CML (1974–2012). Only 5 of these cases have been on Imatinib, for a duration ranging between 7 and 65 months. There were no reports about other tyrosine kinase inhibitors (TKI). This is the first reported case of MM on top of CML while on Nilotinib, and after the longest duration on Imatinib.

Tyrosine kinase inhibitors (TKI) constitute a revolution in the treatment of CML. With marked improvement of survival, patients are now prone to other malignancies. Reporting more cases will help understand the long term effects of TKIs.

No relevant conflicts of interest to declare.