Abstract
Chronic myeloid leukemia is a myeloproliferative neoplasm characterized by the unregulated and abnormal proliferation of both mature and immature granulocytes, which results in the proliferation of peripheral blood leukocytes. Imatinib, a tyrosine kinase inhibitor, is the first-line treatment for patients diagnosed with chronic myeloid leukemia. However, despite its favorable safety profile, imatinib use is associated with a number of side effects. Gynecomastia is a rare adverse effect of imatinib treatment and may be associated with an imbalance in sex hormones. The present study reports the case of a patient with chronic myeloid leukemia diagnosed with gynecomastia after imatinib treatment. The aim of the present report was to highlight to clinicians this adverse reaction to imatinib treatment and investigate a treatment strategy with fewer side effects.