Time-dependent changes in kidney histopathology in ethylene glycol poisoning

Ethylene glycol (EG) may be acutely toxic following ingestion. In fatal cases, microscopic examination of urine and kidney specimens can establish a post-mortem diagnosis of EG poisoning. We describe the main renal histopathologic changes during different stages of EG poisoning, which might be helpful when dating the EG poisoning itself. A single-centre retrospective study conducted on all EG poisoning cases demonstrated that in an early stage of EG poisoning, fine dust-like crystals were deposited to the tubular cell basement membrane, followed by internalisation of calcium oxalate crystals into the epithelial cells. Later, the crystals formed larger aggregates within the epithelial cells. As the changes became advanced, pronounced tubular epithelial damage occurred, with detachment of epithelial cells from the basement membrane. In the final stage, coarse calcium oxalate crystals were recognised in the tubular lumen, with cellular debris from damaged epithelial cells. Our study shows that the time-dependent histological changes described follow the clinical stages of EG poisoning and may therefore provide a rough estimate of the time of EG ingestion before death.