Cystinuria is the most common kidney stone disease with Mendelian genetics. Caused by mutations in SLC7A9 and SLC3A1, affected patients excrete high amounts of cystine in their urine and are vexed by recurrent episodes of nephrolithiasis. Cystine stones…
This is a fictional case, designed for educational purposes The Case The patient is a 66 year-old with a history of hypertension who presented with complaints of fatigue and recurrent “sinus infections” over the past few months. He…
Eric Bywaters was the first to use the nomenclature “pigmented casts” in a 1941 British Medical Journal publication about crush syndrome where he illustrates pigmented casts (due to myoglobin) with a photomicrograph (Figure 1) of the kidney biopsy…
Hyaline casts are traditionally known to lack clinical significance. However, because they are frequently found during urinary sediment microscopy, hyaline casts should be correctly identified and distinguished from other types of casts. They are colorless transparent cylindrical structures…
After centrifugation of the urine specimen, the macroscopic appearance of the sedimentation can offer certain clues about the nature of the urinary sediment. Color is by far the most important characteristic to define different sedimentations, but other features…
In order to interpret your findings after collecting and preparing a urine specimen for microscopy you must obtain a high quality image. If you are not able to clearly see what you’re examining, it may be quite difficult…
Several types of organisms can be identified in the urine sediment. Bacteria, fungi, and parasites are 3 classes of microorganims that can be found. 1. Bacteria Rods and cocci can be identified in the urine sediment and urinary…
Most urinary casts have a fairly homogenous aspect throughout their entirety and are clearly classifiable as either hyaline, granular (with all their variants), waxy, or of some cellular nature. However, in many instances urinary casts are not homogenous…
Crystals are a frequent finding in the urinary sediment. Besides microcrystalline deposits (amorphous phosphates and urates), the most common types of crystals in my practice are: 1. CaOxalate dihydrate (COD) 2. CaOxalate monohydrate (COM) 3. Uric acid …
BK virus (BKV) is a DNA virus that infects up to 90% of the adult population. After initial exposure in childhood, the virus becomes latent in urothelial tissues. In transplant patients, BKV can reactivate in the context of…