Abstract
Dasatinib is a drug for treatment of oncogene fusion protein BCR-ABL-positive chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia resistant/intolerant to imatinib. Pleural effusion (PE) is a common adverse effect, and in this context, we present four cases seen due to this cause. One of them is a chylothorax. The PE grade is variable, and the physiopathology is not well established, although a block in T-lymphocyte function or inhibition of platelet-derived growth factor receptor-β is suggested being involved. The PE is generally a lymphocyte-predominant exudate, but can also present as chylothorax. Several factors have been associated with its appearance, particularly the administration in two daily doses. Low grade (1-2) PEs usually respond well to interrupt the treatment while those of higher grade may also require therapeutic thoracentesis and corticosteroids. There are currently no firm guidelines that establish when to resort to one form of treatment or another.