2024 Volume 73 Issue 3 Pages 588-594
Ammonium urate (AU) crystals in urine sediment showed various shapes that were not found in the atlas, such as sea urchin-like, needle-like, radial spherical, and dumbbell-like (iron array-like). Case 1: Female in her 30s, 6 months pregnant. Three weeks prior, she was admitted to the urology department of our hospital for bilateral hydronephrosis in another prefecture and received only intravenous drip treatment. Due to persistent dull pain, she visited the urology department of our hospital for letter of reference. Many sea urchin-like, needle-shaped, yellow-brown crystals were observed in the urine sediment. Case 2: Female in her 90s. After being admitted to our hospital’s community comprehensive care ward from another hospital, tests were conducted to assess her condition and check for fever. Yellowish brown crystals in the form of radial spheres and iron arrays were found in the urine sediment. In both cases, it was difficult to diagnose by microscopic examination, therefore crystals were collected and stone analysis was performed, which revealed acidic AU. AU crystals are spherical with spines, but this case showed that they can take a variety of shapes, including sea urchin-like, needle-like, radial spherical, and iron array-like shapes.
