Dasatinib as a Probable Cause of Bilateral Chylothorax in a Patient with Chronic Myeloid Leukemia: Case Report

Dasatinib-induced chylothorax has been sporadically reported, and its pathophysiology has yet to be fully elucidated. We report a 53-year-old man with underlying chronic myeloid leukemia in remission on regular dasatinib who was referred to pulmonology team with an incidental finding of a right upper lobe lung nodule with bilateral pleural effusion on chest radiograph. Computed tomography confirmed a solid spiculated solitary pulmonary nodule (SPN) with bilateral pleural effusions with no mediastinal or intra-abdominal lymphadenopathy. Initial diagnostic thoracentesis of the left pleural effusion revealed serous fluid, which was exudative with negative cytology and medical thoracoscopic pleural biopsy yielded only chronic inflammatory changes. Post-procedurally, as appetite further improved, intercostal tube drainage turn chylous, centrifugation and triglyceride levels confirmed chylothorax. Diagnostic thoracentesis was then done over the right pleural effusion, which revealed serous appearance, biochemically exudative with triglyceride of 1.7 mmol/l. Bilateral chylothorax probably due to dasatinib was suspected, and the drug was withheld. Chest tube was removed after 10 days. PET/CT scan showed only hypermetabolism in the SPN and hilar lymph node with no mediastinal involvement. Tuberculosis workup was negative. The SPN was biopsied under fluoroscopy-guided bronchoscopy, which confirmed limited stage neuroendocrine carcinoma of the lung. Patient remained well at 1 month follow-up with no recurrence of bilateral chylothorax. We discuss the implications of concurrent bilateral exudative chylothorax in SPN and the diagnostic challenges of chylothorax.