Reversible posterior leukoencephalopathy syndrome (RPLS) in a patient with chronic lymphocytic leukemia (CLL) treated with Acalabrutinib, a Bruton's tyrosine kinase (BTK) inhibitor: a case report.

RPLS is a rare neuroradiologic syndrome characterized by headache, visual disturbances, focal deficits and confusion. There are several underlying mechanisms causing RPLS, including arterial hypertension and renal failure, but also treatments with immunosuppressive therapy, chemotherapy or targeted therapy (such as small molecule inhibitors). Acalabrutinib is a novel second-generation BTK inhibitor, frequently used as treatment for B-cell malignancies. Here, we present a case of RPLS in a CLL patient treated with Acalabrutinib, for 18 months. A 76-year-old male, with a history of arterial hypertension and kidney disease, experienced throbbing headache and visual disturbances and was diagnosed with RPLS based on the typical high parietal subcortical hyperintensities on FLAIR MRI. Due to the effective management of his aggravated hypertension, the new MRI lesions were resolved at the follow-up scan after one month. We conclude that, in patients treated with a BTK inhibitor like Acalabrutinib, clinicians should pay special attention to the development of a new or worsened hypertension or the development of a new headache, visual disturbances or other symptoms that may indicate RPLS.