Serositis causing pericardial and pleural effusions after eight years of maintenance ibrutinib for Waldenstrom's macroglobulinemia

Ibrutinib is a tyrosine kinase inhibitor approved for multiple B-cell malignancies, including Waldenstrom's macroglobulinemia in 2014. Although the drug portends favorable outcomes, it also bears a profile of side effects. Current literature describes only two cases of nonhemorrhagic pericardial effusion associated with ibrutinib use, and here we present the third. This case recounts an episode of serositis causing pericardial and pleural effusions and diffuse edema after eight years of maintenance ibrutinib for Waldenstrom's macroglobulinemia (WM).A 90-year-old male with WM and atrial fibrillation presented to the emergency department for a week of progressive periorbital and upper and lower extremity edema, dyspnea, and gross hematuria, despite increasing at-home diuretic dose. The patient was on 140 mg ibrutinib twice daily. Labs showed stable creatinine, serum IgMs of 97, and negative serum and urine protein electrophoresis. Imaging revealed bilateral pleural effusions and pericardial effusion with impending tamponade. All other workup was unrevealing, diuretics were ceased, pericardial effusion was monitored with serial echocardiograms, and ibrutinib was exchanged for low-dose prednisone.After five days, the effusions and edema dissipated, hematuria resolved, and patient was discharged. Resumption of lower dose ibrutinib one month later led to a subsequent return of edema, which again subsided with cessation. Reevaluation of maintenance therapy continues outpatient.Patients on ibrutinib presenting with dyspnea and edema should be monitored for pericardial effusion; the drug should be held in exchange for anti-inflammatory therapy, and future management should involve cautious, low-dose resumption, or exchange for alternative therapy.