Leukocytosis: The mysteries within


67-year-old male was referred to our clinic for evaluation of progressive lymphocytosis and was diagnosed with chronic lymphocytic leukemia (CLL) by peripheral blood flow cytometry. On top of lymphocytosis (30.8 K/μL), other abnormalities were seen on the complete blood count and differential as basophilia (13.2 K/μL), eosinophilia (9.5 K/μL), monocytosis (2.3 K/μL), and neutrophilia (49.8 K/μL), hence a bone marrow aspirate (Image 1 Panel A) and biopsy (Image 1 Panel B) were performed showing myeloid hyperplasia. Fluorescent in-situ hybridization (FISH) showed 74% t(9;22) confirming a diagnosis of concurrent chronic myelogenous leukemia (CML) and CLL. The patient achieved complete hematological, cytogenetic and molecular remission 6 months after starting imatinib mesylate for CML. The follow-up bone marrow biopsy, molecular studies, and peripheral blood smear showing smudge cells (Image 1 Panel C) were all compatible with CLL with no evidence of CML.

Illustration 1.