What are pigmented casts?
Pigment casts Formed by the adhesion of metabolic breakdown products or drug pigments, these casts are so named due to their discoloration. Pigments include those produced endogenously, such as hemoglobin in hemolytic anemia, myoglobin in rhabdomyolysis, and bilirubin in liver disease.
Can granular casts be normal?
Casts in urine from normal individuals are few or none (and are usually hyaline or granular in nature).
What causes casts in urine?
Casts are the result of solidification of material (protein) in the lumen of the kidney tubules, more specifically in the nephron. Once formed, these molds (or casts) of the tubule are eliminated via the urine and may be seen in the urine sedi- ment.
What does it mean if there is sediment in urine?
The most common cause of sediment in the urine is a urinary tract infection. In this case, the urine will contain cells, especially white blood cells, or pus. This type of sediment typically looks cloudy instead of flaky. The urine may have an odor.
Can you see cellular casts in urine?
If a cellular cast is seen in the urine, it is known that the cells were present in the kidney (nephron). Although causes and severity differ, the presence of cellular casts indi- cates a disease process.
Which condition promotes the formation of casts in the urine?
The following factors promote the formation of casts in the kidney: Larger than normal amounts of plasma proteins entering the tubules. Decreased pH. Decreased urinary flow rate.
How are casts formed?
Casts are cylindrical bodies formed either in the distal convoluted tubules or the collecting ducts of the kidney. Since the walls of the tubule act as a mold for cast formation, the width of the tubule determines the width of the cast.
What is the color of a granular cast?
Figure 2 illustrates the usual color of granular casts; Figure 3 illustrates the usual color of renal tubular epithelial cell (RTEC) casts; and, Figure 4 illustrates the usual color of waxy casts. As can be seen in the images, granular and RTEC casts present a greyish color scale and the waxy cast presents a yellowish/greenish/grayish color scale.
What does a granular cast in urine mean?
Granular casts are casts that contain either proteins, tubular cells or leukocytes that have broken down. The presence of granular casts in the urine does not indicate the type of kidney disease present. Medicine that links medical knowledge with data to predict a patient’s potential health problems.
Who was the first to use the term pigmented casts?
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 [1-3].
What are pigment granules and what do they look like?
Pigment granules are small, dark, and solid structures that are granular in appearance and considerably smaller than cortical fusi. The rather ample cytoplasms of the chief cells were amphophilic to clear and contained a variable number of coarse brown-black pigment granules (Figures 2 and 3, A).