Cryptococcal Infection in a Patient With Chronic Lymphocytic Leukaemia Receiving Acalabrutinib, a Bruton's Tyrosine Kinase Inhibitor: A Case Report.

A male patient in his mid-sixties with chronic lymphocytic leukaemia (CLL), Binet stage B, receiving the Bruton's tyrosine kinase (BtK) inhibitor acalabrutinib, presented with fever and other non-specific systemic symptoms. Following the investigation, they were found to have Cryptococcal meningitis. Cryptococcal infections are known to occur in immunocompromised patients, but they are rarely encountered or thought about during the initial acute medical assessment. This case highlights the importance of considering the possibility of opportunistic infections and the atypical presentation of such infections in immunocompromised patients, including those on BtK inhibitors.