Fungal CNS infections in patients with hematologic malignancy.

Various fungal agents can cause CNS infections. CNS fungal infections may present as a mass (i.e., brain abscess) typically in the course of aspergillosis or zygomycosis, or may primarily involve the meninges (i.e., meningitis), as can be observed in patients with candidiasis or cryptococcosis. Most commonly, fungal brain abscesses are due to aspergillosis. CNS aspergillosis is observed particularly in acute leukemia and allogeneic hemopoietic stem cell transplantation patients. Usually, aspergillosis is localized in the lungs and secondarily spreads to the brain; only in few cases does it develop as solitary localization of CNS. In these conditions, diagnosis is very difficult because signs and symptoms can be completely aspecific. Diagnosis can often be performed only through aggressive procedures (i.e., stereotactic puncture). Zygomycetes are the second most frequent cause of brain abscesses. CNS involvement is higher than in the course of invasive aspergillosis, and this fungal complication is also characterized by a high mortality rate. In vitro and in vivo studies demonstrated that only posaconazole and lipid formulations of amphotericin B present some possibility of success in the treatment of zygomycosis, but the pharmacologic approach should always be associated with surgery. Among molds, other agents (i.e., Fusarium and Scedosporium) may also be responsible for fungal abscess. More rarely during the course of a hematologic malignancy, a meningeal candidiasis or cryptococcosis may be observed. This review mainly focuses on the epidemiology, clinical manifestations, diagnosis and management strategies of all cases of CNS fungal infections in hematologic patients.