Intradural cauda equina Candida abscess presenting with hydrocephalus: case report.

Central nervous system (CNS) candida infections are often associated with a poor prognosis. Typically, CNS candidiasis presents as meningitis or microabscesses. Here, the authors report a patient with a challenging presentation of a CNS Candida infection as a discrete, large cauda equina abscess. The patient initially presented with ventriculomegaly due to fourth ventricular outflow obstruction and a cauda equina mass. The patient was treated with a ventriculoperitoneal shunt and underwent a lumbar laminectomy for exploration of the lumbar lesion. An intradural abscess was encountered during surgery. Fungal wet mount revealed fungal elements and polymerase chain reaction confirmed the presence of Candida albicans. The patient did not have any known predisposition to fungal infections; therefore, the authors performed whole-exome sequencing using peripheral blood mononuclear cell DNA. They found heterozygous missense variants in the following genes: colony-stimulating factor 2 (CSF2) and Ras protein-specific guanine nucleotide-releasing factor 1 (RASGRF1)-genes that have been specifically associated with protection from CNS candidiasis via caspase recruitment domain-containing protein 9 (CARD9) signaling, and phospholipase C gamma 2 (PLCG2)-a lectin receptor involved in candidiasis. The authors' experience suggests that C. albicans can present as a cauda equina abscess. Hydrocephalus, a result of diffuse arachnoiditis, is a potential complication from intradural fungal abscesses.