Localized upper extremity edema secondary to Bruton's tyrosine kinase inhibition.

Bruton's tyrosine kinase (BTK) inhibitors, such as ibrutinib, acalabrutinib, and zanubrutinib, are commonly used to treat chronic lymphocytic leukemia (CLL), Waldenström macroglobulinemia, and mantle cell lymphoma. These inhibitors can cause cutaneous adverse events, including ecchymoses, skin infections, and hair and nail changes. Edema, or swelling, has been reported in 5-29% of patients treated with BTK inhibitors, but it has not been well classified. This article presents two cases of persistent upper extremity edema in patients on BTK inhibitor therapy and discusses the possible mechanisms and management of this side effect. [Extracted from the article]