Acrophialophora fusispora brain abscess in a child with acute lymphoblastic leukemia: Review of cases and taxonomy

A 12-year-old girl with acute lymphoblastic leukemia was referred to King F aisal Specialist Hospital and Research Center. The diagnosis without centra l nervous system (CNS) involvement was confirmed on admission, and chemothe rapy was initiated according to the Children Cancer Group (CCG) 1882 protoc ol for high-risk-group leukemia. During neutropenia amphotericin B (AMB) (1 mg/kg of body weight/day) was initiated for presumed fungal infection when a computed tomography (CT) scan of the chest revealed multiple nodular den sities. After 3 weeks of AMB therapy, a follow-up chest CT revealed progres sion of the pulmonary nodules. The patient subsequently suffered a seizure, and a CT scan of the brain was consistent with infarction or hemorrhage. B ecause of progression of pulmonary lesions while receiving AMB, antifungal therapy was changed to liposomal AMB (LAMB) (6 mg/kg/day). Despite 26 days of LAMB, the patient continued to have intermittent fever, and CT and magne tic resonance imaging of the brain demonstrated findings consistent with a brain abscess. Aspiration of brain abscess was performed and the Gomori met henamine silver stain was positive for hyphal elements. Culture of this mat erial grew Acrophialophora fusispora. Lung biopsy showed necrotizing fungal pneumonia with negative culture. The dosage of LAMB was increased, and itr aconazole (ITRA) was added; subsequently LAMB was discontinued and therapy was continued with ITRA alone. The patient demonstrated clinical, and radio logical improvement. In vitro, the isolate was susceptible to low concentra tions of AMB and ITRA. A. fusispora is a thermotolerant, fast-growing fungu s with neurotropic potential. We report the first case of human infection i nvolving the CNS. Acrophialophora resembles Paecilomyces but differs in hav ing colonies that become dark and in the development of phialides along the sides or at the tips of echinulate brown conidiophores. Conidia are horne in long chains and are smooth or ornamented with fine-to coarse echinulatio ns, sometimes in spiral bands. The taxonomy of the genus Acrophialophora is reviewed, and Acrophialophora nainiana and Acrophialophora levis are consi dered as synonyms of A. fusispora.