Transformation of Chronic Lymphocytic Leukemia into Acute Mixed Phenotype Leukemia Myeloid/T Neoplasm: a Case Report

Chronic lymphocytic leukemia (CLL) is defined by the presence of lymphocyte in the blood, bone marrow, lymph nodes, and spleen, with a median lymphocyte count of 20–30 × 10 9 /L for more than 3 months. CLL is known to be rarely associated with myeloid malignancies. This study presents a case of CLL, which transformed into myeloid/T neoplasm. A 62-year-old man with a 10-year history of CLL was referred to our hospital because of multiple skin bruises and anemia. He was monitored for 10 years without any treatment until this time when the disease progressed, and chemotherapy was started. After 8 months of treatment completion, he deteriorated. This time, bone marrow biopsy immunophenotyping revealed the transformation of CLL into mixed phenotype acute leukemia myeloid/T neoplasm with no residue of preexisting CLL. Transformation of CLL into acute leukemia may arise from the same clone. Still, there is some evidence that it may be therapy related; hence, any deterioration in a patient with CLL should be evaluated promptly for a better outcome.