ABSTRACT
BACKGROUND: Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder. Plasma cell dyscrasias are a rare heterogeneous group of hematological disorders. The co-occurrence of CML and plasma cell dyscrasias in the same patient is an extremely rare incident and has been reported in several cases in the literature. CASE SUMMARY: In the present report, we described a rare case of the co-occurrence of CML and plasma cell dyscrasias in a 48-year-old man, and we discussed the reason why monoclonal gammopathy of undetermined significance progressed to smoldering multiple myeloma and eventually to multiple myeloma while being treated with dasatinib for CML. The tyrosine kinase inhibitor treatment and cytogenetic change may contribute to this phenomenon, and clonal hematopoiesis of indeterminate potential may lead to both CML and multiple myeloma cells in a patient. Future studies are warranted to further explain the hidden reasons. CONCLUSION: This case highlights that gene translocation may contribute to initiation and sustainability of clonal proliferation. Moreover, the treatment with tyrosine kinase inhibitor and cytogenetic change may contribute to progression from monoclonal gammopathy of undetermined significance to smoldering multiple myeloma and eventually to multiple myeloma.