An acanthocyte is a specific type of dysmorphic erythrocyte with one or more circular membrane bulges. Finding 5% or more acanthocytes the sediment is considered a reliable marker for glomerular hematuria. For this reason, it is recommended that acanthocytes always be reported separately. See also section 6.2.4.4. of the EFLM European Urinalysis Guideline 2023.