2026 Volume 75 Issue 2 Pages 428-432
In ethylene glycol poisoning, oxalic acid—a metabolic byproduct—binds with calcium to form precipitates, resulting in the appearance of characteristic calcium oxalate crystals in the urine. We report a case of ethylene glycol poisoning in a teenage girl, in which urinary sediment findings prompted the diagnosis. The patient was found at home with impaired consciousness and vomiting, and was transported to our hospital by emergency medical services. Blood gas analysis revealed high-anion-gap metabolic acidosis and decreased renal function; microscopic examination of the urinary sediment showed numerous elongated hexagonal crystals. These crystals were insoluble in acetic acid but soluble in hydrochloric acid, and were identified as calcium oxalate. Based on the clinical course and a history of antifreeze ingestion, the appearance of calcium oxalate crystals in urine, the patient was diagnosed with ethylene glycol poisoning due to a suicide attempt, and emergency hemodialysis was initiated. Following treatment, the number of urinary crystals decreased, and renal function improved. Ethylene glycol poisoning is a potentially fatal condition that can cause metabolic acidosis and renal injury, and the presence of elongated hexagonal calcium oxalate crystals in urine serves as an important diagnostic clue. Urinary sediment examination should not be limited to recognizing typical forms; rather, careful attention to morphological diversity and prompt clinical reporting can facilitate timely initiation of treatment.
