Bilateral Chylothorax After 13 Years of Dasatinib Therapy in a Patient With Chronic Myeloid Leukaemia: A Case Report

ABSTRACT A 52‐year‐old man with chronic myeloid leukaemia (CML) who had been receiving dasatinib 100 mg/day for 13 years presented with progressive dyspnea. Chest radiography revealed bilateral pleural effusions, and further evaluation confirmed the diagnosis of chylothorax. Dasatinib‐induced chylothorax was suspected, and discontinuation of the drug led to clinical improvement. Dasatinib is a tyrosine kinase inhibitor (TKI) used for the treatment of CML and Philadelphia chromosome–positive acute lymphoblastic leukaemia (Ph + ALL). Although pleural effusion is a relatively common adverse effect, chylothorax is an extremely rare complication. This case highlights the importance of considering chylothorax as a potential cause of pleural effusion in patients undergoing long‐term dasatinib therapy. In addition, based on the presumed pathophysiological mechanism, drug discontinuation appears to be the most crucial therapeutic approach for dasatinib‐induced chylothorax.