A Tale of Two Hematological Malignancies: CML Followed by CLL in the Same Patient

Abstract

Studies have reported second malignancies occurring in patients with chronic myeloid leukemia (CML) or chronic lymphoid leukemia (CLL). We discuss the case of a 77-year-old man diagnosed with CLL who later developed CML. The CLL was managed with surveillance after diagnosis for 3 years and later treated with ibrutinib and venetoclax. While on treatment with venetoclax for 4 months, the patient had worsening leukocytosis shown via peripheral flow cytometry and fluorescence in situ hybridization, with the presence of myeloid lineage cells positive for BCR-ABL and complete disappearance of lymphoid cells. This case report highlights the importance of considering a second malignancy in hematologic malignancies with variable disease prognosis.