1 URINALYSIS

2 UA Casts

3 Cast Formation Urinary casts are formed only in the distal convoluted tubule (DCT) or the collecting duct (distal nephron). The proximal convoluted tubule (PCT) and loop of Henle are not locations for cast formation. Hyaline casts are composed primarily of a mucoprotein (Tamm-Horsfall protein) secreted by tubule cells. The Tamm-Horsfall protein secretion (green dots) is illustrated in the diagram below, forming a hyaline cast in the collecting duct:

4 Cast Formation Cast are molded in the lumen of the renal tubules Formed in Distal and Collection tubules Composed of plasma proteins of Glomerular Filtrate Tamm-Horsfall Protein makes up matrix

5 Cast Names Named by how they appear Convoluted Broad Granular (Finely or Coarsely granular) Waxy

6 Cast Names Named by what is in casts Cells WBC, RBC, Renal Epithelial or Mixed Substances Fat Hemoglobin

7 Casts

8 Fiber Don’t mistake fibers for casts!!!!

9 Hyaline Casts Low refractive Index Difficult to see Use low light

10 Hyaline Casts Cylindroid Hyaline cast with tail

11 Hyaline Cast Mucous Threads Phase Contrast

12 Hyaline Cast Spermatozoa Tortuouse Cigar Shaped Phase Contrast

13 Hyaline Cast Tortuous Interference Contrast

14 Hyaline Cast Triple Phosphate Note how Hyaline Casts are barely visible

15 Hyaline Cast Convoluted Note cells on matrix

16 Granular Casts Formed by the breakdown of cellular casts In patients with renal disease the granules become more fine as they progress through the nephron and eventually become Waxy

17 Cast Degeneration

18 Finely Granular Cast C

19 Finely Granular Cast Higher refractive index than Hyaline cast May be present in urine of healthy person after severe physical exercise Found in all forms of renal disease

20 Coarse Granular Cast Granules may be disintegrated RBC’s due to reddish color

21 Coarse Granular Cast Sternheimer- Malbin Stain

22 Coarse Granular Cast

23 Coarse Granular Cast Note mucous threads in background

24 Broad Finely Granular Cast In early stage of evolving into waxy cast Notched margins

25 Waxy Cast High Refractive Index Notched parallel margins “Broken Off” ends Chronic renal disease

26 Waxy Cast High Refractive Index Notched parallel margins “Broken Off” ends Chronic renal disease

27 Waxy Cast High Refractive Index Notched parallel margins “Broken Off” ends Chronic renal disease

28 Waxy Cast SM Stain High Refractive Index Notched parallel margins “Broken Off” ends Chronic renal disease

29 Waxy Cast Note Spheric lipid globules on surface Notched parallel margins “Broken Off” ends Chronic renal disease

30 Fatty Casts Casts that contain free fat or oval fat bodies Fat appears as globular lipids of varying size Often have a yellow tan color Lipid has high refractive index Lipid is birefringent Maltese Cross in polarized light

31 Fatty Cast Lipid globules on surface RBC in background Nephrotic Syndrome

32 Fatty Cast Lipid globules on surface RBC in background Nephrotic Syndrome Polarized Maltese Cross

33 Fatty Cast Lipid globules on surface RBC in background Nephrotic Syndrome Polarized Maltese Cross

34 Fatty Cast Lipid globules on surface RBC in background Nephrotic Syndrome Polarized Maltese Cross

35 Fatty Cast Lipid globules on surface RBC in background Nephrotic Syndrome

36 Fatty Cast Polarized

37 Broad Red Cell Casts

38 Cast Formation in Nephron Cellular Cast are named for the types of cells they contain

39 Cellular Cast formation

40 Hemoglobin Cast ?? Reddish color

41 RBC Cast RBC in hyaline cast matrix RBC more concentrated at one end

42 RBC Cast RBC in hyaline cast matrix Surrounding urine filled with PMN’s and RBC

43 RBC Cast RBC in hyaline cast matrix

44 RBC Cast RBC in hyaline cast matrix Very difficult in this cast to see intact RBC’s Hb granules

45 Cellular Cast Mixed Epi’s WBC Note yeast

46 Cellular Cast Renal Tubular Cells

47 Cast Review

48 Casts Overhead