Urine Sediment of the Month: Pigmented Casts & What Those Pretty Colors Tell Us
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…
Urine Sediment of the Month: Colorless, Transparent Hyaline Casts
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…
Urine Sediment of the Month: The Visible Sediment
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…
Urine Sediment of the Month: How to Get a High Quality Image
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…
Urine Sediment of the Month: Microorganisms
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…
Urine Sediment of the Month: Mixed, Acellular Casts
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…
Urine Sediment of the Month: Common Crystals!
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 …
Urine Sediment of the Month: Don’t be Fooled by Decoy Cells…A Clue to BK Polyomavirus Reactivation
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…
Urine Sediment of the Month: White Blood Cells, “Glitter Cells”, and WBC Casts
White blood cells (WBC’s) in the urine may occur as a result of infection or inflammation anywhere in the urinary tract and the segmented polymorphonuclear neutrophil is the type most often encountered. These WBC’s are identified by the…
Urine Sediment of the Month: Granular & “Muddy Brown” Casts
Perhaps that most highly sought finding in urinary sediment microscopy is the presence of granular casts. In clinical grounds, granular casts are typically associated with acute tubular injury (ATI) and guide the differentiation between prerenal and overt tubular…
