RESUMEN
Chronic myeloid leukemia is characterized by a unique reciprocal translocation between chromosomes 9 and 22 resulting in deregulated tyrosine kinase activity. Tyrosine kinase inhibitors, such as imatinib, dasatinib, and nilotinib have revolutionized treatment of Chronic myeloid leukemia. However, tyrosine kinase inhibitors' use has presented new challenges in managing both acute and chronic toxicities, particularly 'off-target' toxicities like pleural effusion. Pleural effusions are seen less often with imatinib and very rarely with nilotinib. A 66-year-old male presented to emergency department with complaints of mild chest pain and dyspnea of 3 days duration with progressive worsening, including dyspnea at rest. Patient was currently taking nilotinib after failing imatinib for chronic myeloid leukemia. Nilotinib was put on hold. After exclusion of cardiac and pulmonary etiologies patient was treated for community acquired pneumonia with minimal improvement. Despite the very low incidence of pleural effusion with nilotinib (<1%), he was started on 20 mg of prednisone PO for 3 days. Patient had a dramatic improvement within 48 h after beginning prednisone. This treatment approach suggests that pleural effusions associated with nilotinib can be successfully treated in the same way as pleural effusions associated with dasatinib.