Microscopic_Examination_of_Urine_pdf.pdf

Urine Microscopy

1. Microscopic
Examination of Urine
PREPARED BY: CAMILLE ANN CASTILLO, RMT

2. Macroscopic screening (chemical sieving)
Screening Test Significance
Color Blood
Clarity Hematuria versus
hemoglobinuria/myoglobinuria
Confirm pathologic or non-
pathologic cause of turbidity
Blood RBCs/RBC casts
Protein Casts/cells
Nitrite Bacteria/WBCs
Leukocyte esterase WBCs/WBC casts/bacteria
Glucose Yeast

3. Preparation and Examination of the
Urine Sediment
Thomas Addis (1926)
Hemocytometer
12-hour specimen
RBCs, WBCs, casts, and epithelial cells
used primarily to monitor the course of diagnosed
cases of renal disease

4. Preparation of the Urine Sediment
Freshly voided urine
midstream clean-catch specimen
10 and 15 mL (12ml) 
Centrifuged for 5 mins@ 400RCF
0.5-1.0 mL left after decantation
Represents urinary sediments
Agitate
Place a drop (20 μLor 0.02 mL) of centrifuged urine in a
slide + glass cover slip (22 X 22 mm )
Read microscopically

5. Examination of the Urine Sediment
Observe minimum of 10 fields [both low & high PF]
LPF (10x) 
detect casts and to ascertain the general
composition of the sediment
HPF (40x) 
Identification
casts have a tendency to locate near the edges of
the cover slip (LPF scanning around the cover slip
perimeter)

6. Examination of the Urine Sediment
Bright field microscopy (unstained sediments)
Artifacts are larger than urinary sediments
Reportingof Microscopic Sediments
Sediment Reporting Comment
Casts Lpf 10 fields
RBCs, WBCs Hpf
Epithelial cells,
crystals, and
other elements
Semi-
quantitative
terms
rare, few, moderate, and
many, or as 1+, 2+, 3+, and
4+, following laboratory
format as to lpfor hpfuse

7. Reportingof Microscopic Sediments
Manner of
Reporting
Comment
Occasional 0-1, 0-3/HPF at 10 fields
Few 0-4,2-5/HPF at 10 fields
Some 3-5, 8-10/HPF at 10 fields
Moderate More than 10/HPF at 10 fields
Many Abundant/HPF
TNTC Toonumerous to count (loaded)
Examination of the Urine Sediment

8. Sediment Examination Techniques (Stains)
Stain Action Function
Sternheimer-
Malbin(Crystal
violet & Safranin
O)
Delineates structure
and contrasting
colors of the nucleus
and cytoplasm
Identifies WBCs,
epithelial cells, and
casts
Toluidine blue Enhances nuclear
detail
Differentiates WBCs
and renal tubular
epithelial (RTE) cells
2% acetic acid Lyses RBCs and
enhances nuclei of
WBCs
Distinguishes RBCs
from WBCs, yeast,
oil droplets, and
crystals

9. Sediment Examination Techniques (Stains)
Stain Action Function
Lipid Stains: Oil
Red O and
Sudan III
Stains triglycerides
and neutral fats
orange-red
Identifies free fat droplets
and lipid-containing cells
and casts
Gram stain Differentiates gram-
positive and gram-
negative bacteria
Identifies bacterial casts
Hansel stain Methylene blue and
eosin Y stains
eosinophilicgranules
Identifies urinary
eosinophils
Prussian blue
stain
Stains structures
containing iron
Identifies yellow-brown
granules of hemosiderin in
cells and casts

10. Expected Staining Reactions of Sediment
Constituents
Elements in
Urinary Sediment
Usual Distinguishing Color of
Stained Elements
Comments
RBCs Neutral—pink to purple
Acid—pink (unstained)
Alkaline—purple
Hyaline casts Pale pink or pale purple Very uniform color;
slightly darker than
mucous threads
Coarse granular
inclusion casts
Dark purple granules in
purple matrix
Finely granular
inclusion casts
Fine dark purple granules in
pale pink or pale purple
matrix

11. Expected Staining Reactions of Sediment
Constituents
Elements in Urinary
Sediment
Usual Distinguishing Color of
Stained Elements
Comments
Nuclei Cytoplasm
WBCs (dark-staining
cells)
Purple Purple granules
Glitter cells
(Sternheimer-
Malbinpositive
cells)
Colorless or
light blue
Pale blue or gray Some glitter
cells exhibit
brownian
movement
Renal tubular
epithelial cells
Dark shade of
blue-purple
Light shade of
blue-purple
Bladder tubular
epithelial cells
Blue-purple Light purple
Squamous
epithelial cells
Dark shade of
orange-purple
Light purple or
blue

12. Expected Staining Reactions of Sediment
Constituents
Elements in Urinary
Sediment
Usual Distinguishing
Color of Stained
Elements
Comments
Waxy casts Pale pink or pale purple Darker than hyaline casts, but
of a pale even color; distinct
broken ends
Fat inclusion casts Fat globules unstained
in a pink matrix
Rare; presence is confirmed if
examination under polarized
light indicates double
refraction
Red cell inclusion
casts
Pink to orange-red Intact cells can be seen in
matrix
Blood (hemoglobin)
casts
Orange-red No intact cells

13. Expected Staining Reactions of Sediment
Constituents
Elements in Urinary
Sediment
Usual Distinguishing
Color of Stained
Elements
Comments
Bacteria Motile: do not stain
Nonmotile: stain
purple
Motile organisms are not
impaired
Trichomonas
vaginalis
Light blue-green Motility is unimpaired in fresh
specimens when
recommended volumes of
stain are used; immobile
organisms also identifiable
Mucus Pale pink or pale blue
Background Pale pink or pale
purple

14. CytodiagnosticUrine Testing
preparation of permanent slides using
cytocentrifugation
Staining with Papanicolaoustain
Detection of malignancies of the lower urinary tract
First morning specimen
provides more definitiveinformation about renal tubular
changes associated with transplant rejection; viral,
fungal, and parasitic infections; cellular inclusions;
pathologic casts; and inflammatory conditions

15. Urinalysis Microscopic Techniques
Technique Function
Bright-field microscopy Used for routine urinalysis
Phase-contrast microscopy Enhances visualization of
elements with low refractive
indices, such as hyaline casts,
mixed cellular casts, mucous
threads, and Trichomonas
Polarizing microscopy Aids in identification of
cholesterol in oval fat bodies,
fatty casts, and crystals

16. Urinalysis Microscopic Techniques
Technique Function
Dark-field microscopy Aids in identification of
Treponemapallidum
Fluorescence microscopy Allows visualization of naturally
fluorescent microorganisms or
those stained by a fluorescent
dye
Interference-contrast Produces a three-dimensional
microscopy-image and layer-
by-layer imaging of a specimen

17. Sediment Constituents
Red Blood Cell (RBC)
Pointof reference Description
Appearance •Non-nucleated biconcave disks
•Crenatedin hypertonic urine
•Ghost cells in hypotonic urine
•Dysmorphicwith glomerular
membrane damage
Sources of
Identification error
•Yeast cells
•Oil droplets
•Air bubbles
Reporting Average number per 10 hpfs
Complete urinalysis
correlation
•Color
•Reagent strip blood reaction

18. Sediment Constituents (RBC)

20. Sediment Constituents
White Blood Cell (WBC)
Pointof reference Description
Appearance •Larger than RBCs (12μ diameter)
•Granulated, multilobedneutrophils
•Glitter cells in hypotonic urine
•Mononuclear cells with abundant
cytoplasm
Sources of
Identification error
•Renal tubular epithelial cells
Reporting Average number per 10 hpfs
Complete urinalysis
correlation
•Leukocyte esterase
•Nitrite
•Specific gravity
•pH

21. Sediment Constituents (WBC)

23. Sediment Constituents
Epithelial Cells (Squamous)
Pointof reference Description
Appearance •Largest cells in the sediment with
abundant, irregular cytoplasm and
prominent nucleii
Sources of
Identification error
•Rarely encountered, folded cells may
resemble casts
Reporting •Rare, few, moderate, or many per lpf
Complete urinalysis
correlation
•Clarity

24. Squamous Epithelial Cell

26. Sediment Constituents
Epithelial Cells (Transitional/Urothelial)
Pointof reference Description
Appearance •Spherical, polyhedral, or caudate
with centrally located nucleus
Sources of
Identification
error
•Spherical forms resemble RTE cells
Reporting •Rare, few, moderate, or many per
hpf
Complete
urinalysis
correlation
•Clarity; blood, if malignancy-
associated

27. Transitional (Urothelial) Epithelial Cells

28. Sediment Constituents
Epithelial Cells (Renal Tubular)
Pointof reference Description
Appearance •Rectangular, columnar, round, oval or,
cuboidal with an eccentric nucleus possibly
bilirubin-stained or hemosiderin-laden
Sources of
Identification
error
•Spherical transitional cells Granular casts
Reporting •Average number per 10 hpfs
Complete
urinalysis
correlation
•Leukocyte esterase and nitrite (pyelonephritis)
•Color *Clarity
•Protein *Bilirubin (hepatitis)
•Blood

29. Renal Tubular Epithelial Cells

30. Sediment Constituents
Oval Fat Bodies
Pointof reference Description
Appearance •Highly refractileRTE cells
Sources of
Identification
error
•Confirm with fat stains and
polarized microscopy
Reporting •Average number per hpf
Complete
urinalysis
correlation
•Clarity
•Blood
•Protein
•Free fat droplets/fatty casts

31. Oval Fat Bodies

32. Sediment Constituents
Bacteria
Pointof reference Description
Appearance •Small spherical and rod-shaped
structures
Sources of
Identification error
•Amorphous phosphates and urates
Reporting •Few, moderate, or many per hpf, the
presence of WBCs may be required
Complete urinalysis
correlation
•pH
•Nitrite
•LE
•WBCs

33. Bacteria

34. Sediment Constituents
Yeast
Pointof reference Description
Appearance •Small, oval, refractilestructures with
buds and/or mycelia
Sources of
Identification error
•RBCs
Reporting •Rare, few, moderate, or many per hpf,
the presence of WBCs may be required
Complete urinalysis
correlation
•Glucose
•LE
•WBCs

35. Yeast

36. Sediment Constituents
Parasites (Trichomonas)
Pointof reference Description
Appearance •Pear-shaped, motile, flagellated
Sources of
Identification error
•WBCs
•renal tubular epithelial cells
Reporting •Rare, few, moderate, or many per
hpf
Complete
urinalysis
correlation
•LE
•WBCs

37. Parasites

38. Sediment Constituents
Spermatozoa
Pointof reference Description
Appearance •Tapered oval head with long, thin
tail
Sources of
Identification error
•None
Reporting •Present, based on laboratory
protocol
Complete
urinalysis
correlation
•Protein

39. Spermatozoa

40. Sediment Constituents
Mucus
Pointof reference Description
Appearance •Single or clumped threads with a
low refractive index
Sources of
Identification error
•Hyaline casts
Reporting •Rare, few, moderate, or many per
lpf
Complete
urinalysis
correlation
•None

41. Mucus

42. Urine Casts
Unique to kidney
Formed within the lumen of DCT & CD
Provides microscopic view of condition w/in
nephron
Lpfdetection/Scanning around cover slip edge
Low refractive index observe in subdued light
Reporting: Ave. #/10 lpf

43. Casts (Composition and Formation)
Tamm-Horsfallprotein
-major constituent of cast
-stress & exercise
Albumin, immunoglobulin
Protein gel urine-flow stasis, acidity, Na
+
, Ca
++
Tapered end formed at the junction of ALH & DCT
-cylindroids
Cylindruriapresence of urinary cast

44. Hyaline Casts
Pointof reference Description
Appearance •Colorless homogenous matrix
Sources of
Identification error
•Mucus, fibers, hair, increased lighting
Reporting •Average number per lpf
Complete urinalysis
correlation
•Protein -Blood (exercise)
•Color (exercise)
Clinical significance•Glomerulonephritis
•Pyelonephritis
•Chronic renal disease
•Congestive heart failure
•Stress and exercise

45. Hyaline Casts

46. RBC Casts
Pointof reference Description
Appearance •Orange-red color, cast matrix
containing RBCs
Sources of
Identification error
•RBC clumps
Reporting •Average number per lpf
Complete
urinalysis
correlation
•RBCs
•Blood
•Protein
Clinical
significance
•Glomerulonephritis
•Strenuous exercise

47. RBC Casts

48. WBC Casts
Pointof reference Description
Appearance •Cast matrix containing WBCs
Sources of
Identification error
•WBC clumps
Reporting •Average number per lpf
Complete
urinalysis
correlation
•WBCs Protein LE
Clinical
significance
•Pyelonephritis
•Acute interstitial nephritis

49. WBC Casts

50. Bacterial Casts
Pointof reference Description
Appearance •Bacilli bound to protein matrix
Sources of
Identification error
•Granular casts
Reporting •Average number per lpf
Complete
urinalysis
correlation
•WBC cast -WBCs
•LE -Nitrite
•Protein -Bacteria
Clinical
significance
•Pyelonephritis

51. Epithelial Cell Casts
Pointof reference Description
Appearance •RTE cells attached to protein matrix
Sources of
Identification error
•WBC cast
Reporting •Average number per lpf
Complete
urinalysis
correlation
•Protein RTE cells
Clinical
significance
•Renal tubular damage

52. Epithelial Cell Casts

53. Fatty Casts
Pointof reference Description
Appearance Fat droplets and oval fat bodies
attached to protein matrix
Sources of
Identification error
Fecal debris
Reporting •Average number per lpf
Complete
urinalysis
correlation
•Protein
•Free fat droplets
•Oval fat bodies
Clinical
significance
•Nephroticsyndrome
•Toxic tubular necrosis
•Diabetes mellitus -Crush injuries

54. Fatty Casts

55. Granular Casts
Pointof reference Description
Appearance Coarse and fine granules in a cast
matrix
Sources of
Identification error
•Clumps of small crystals
•Columnar RTE cells
Reporting •Average number per lpf
Complete urinalysis
correlation
•Protein
•Cellular casts
•RBCs& WBCs
Clinical
significance
•Glomerulonephritis
•Pyelonephritis
•Stress and exercise

56. Granular Casts

57. Waxy Casts
Pointof reference Description
Appearance •Highly refractilecast with jagged ends
and notches
Sources of
Identification error
•Fibers and fecal material
Reporting •Average number per lpf
Complete urinalysis
correlation
•Protein
•Cellular casts
•Granular casts
•WBCs& RBCs
Clinical
significance
•Stasis of urine flow
•Chronic renal failure

58. Waxy Casts

59. Broad Casts
Pointof reference Description
Appearance •Wider than normal cast matrix
Sources of
Identification error
•Fecal material, fibers
Reporting •Average number per lpf
Complete
urinalysis
correlation
•Protein
•WBCs& RBCs
•Granular casts
•Waxy casts
Clinical
significance
•Extreme urine stasis
•Renal failure

60. Urine Crystals
detect the presence of the relatively few
abnormal types
-liver disease
-inborn errors of metabolism
-renal damage
Reporting: rare, few, moderate, or many per hpf
Abnormal crystals average number per lpf

61. Urine Crystals
formed by the precipitation of urine solutes
Subject to: changes in temperature, solute
concentration, and pH (affect solubility)
Rapidly precipitates at low temperature
Presence of crystals in fresh urine high sp. Gr.
pH determine type of crystal present
*Organic & iatrogenic compounds ppts. In acidic
pH
*inorganic salts pptsin neutral & alkaline sol’n
*except: CaOxpptsin acidic & neutral urine

62. Normal Crystal Seen in Acidic Urine
Crystal Color& Shape Solubility Appearnce
Uric Acid Yellow-brown
(rhombic/4-
sided/rosette)
Alkali
Soluble
Amorphous
urates
Brick dust or
yellow brown
granules
Alkali and
heat
Calcium
oxalate
[Acid/neutral
(alkaline)]
Colorless
(envelopes, oval,
dumbbell,
octahedral)
Dilute HCl

63. Uric acid crystal

64. Amorphous urates

65. Calcium oxalate

66. Normal Crystal Seen in Neutral/Alkaline Urine
Crystal Color& ShapeSolubility Appearnce
Amorphous
phosphates
White–colorless
(granular/white
ppt)
Dilute
acetic
acid
Calcium
phosphate
Colorless (flat
rectangular
plates/thin
prisms often in
rosette
formations)
Dilute
acetic
acid

67. Amophousphosphate

68. Calcium phosphate

69. Normal Crystal Seen in Alkaline Urine
Crystal Color& Shape Solubility Appearnce
Triple
phosphate
Colorless (prism
shape“coffin
lids”)
Dilute
acetic acid
Ammonium
biurate
Yellow-brown
(spicule-covered
spheres “thorny
apples”)
Acetic
acid with
heat
Calcium
carbonate
Colorless
(dumbbells/sphe
rical)
Gas from
acetic acid

70. Triple phosphate (STRUVITE)

71. Ammonium biurate

72. Calcium carbonate

73. Abnormal Crystals seen in Acid Urine
Crystal/Colo
r/shape
Comment Solubility Appearnce
Cystine
•Colorless
•Hexagon
al plates
•Cystinuria
metabolic
disorder of renal
tubules
•Confirmation test
cyanide-
nitroprussidetest
Ammonia,
dilute HCl
Cholesterol
•Colorless
notched
plates
•Seen in
refrigerated
specimen
(dropletform
lipids)
•Nephrotic
syndrome
Chloroform

74. Crystal/ColorComments SolubilityAppearanc
e
Bilirubin
•Yellow
•clumped
needles or
granules
•present in
hepatic
disorders
•positive
chemical test
result for
bilirubin would
be expected
Acetic
acid, HCl,
NaOH,
ether,
chloroform
Radiographic
dye
•Colorless
•Cholesterol
crystal like
•Markedly high
specific gravity
when
measured by
refractometer
10% NaOH
Abnormal Crystals seen in Acid Urine

75. Cystine

76. Cholesterol

77. Bilirubin

78. Radiographic dye

79. Abnormal Crystals seen in Acid/Neutral Urine
Crystal/Color Comments SolubilityAppearance
Leucine
•Yellow-brown
•Spheres
(concentric
circles and
radial striations)
•Crystals Associated
With Liver Disorders
•Presence should be
accompanied by
tyrosine crystals
Hot alkali or
alcohol
Tyrosine
•Colorless–yellow
•Fine needle
(clump or
rosette form)
•seen in conjunction
with leucinecrystals in
specimens with
positive chemical test
results for bilirubin
•May be encountered
in inherited disorders
of amino-acid
metabolism
Alkali or
heat

80. Abnormal Crystals seen in Acid/Neutral Urine
Crystal/Color Comments Solubility Appearance
Sulfonamides
•Varied (olorless to
yellow-brown)
•Needles, rhombics,
whetstones, sheaves
of wheat, and
rosettes
•Seen in inadequate
patient hydration
•possibility of tubular
damage if crystals are
forming in the
nephron
Acetone
Ampicillin
•Colorless
•needles (form
bundles following
refrigeration
•Seen in massive doses
of this penicillin
compound without
adequate hydration
Refrigera-
tionforms
bundles

81. Leucine

82. Tyrosine

83. Sulfonamide

84. Ampicillin

85. Urinary Sediment Artifacts
Contaminants from improper collection
starch, oil droplets, air bubbles, pollen grains,
fibers, and fecal contamination
often very highly refractileor occur in a different
microscopic plane
Not necessarily to be reported

86. Urinary Sediment Artifacts
Artifact Comments Appearance
Starch Granule
•Resemble fat
droplets when
polarized
•Dimpled center
•From cornstarch
used as glove
powder
•Highly refractile
sphere
Oil Droplets
•From OIO
contamination
•highly refractile
and may
resemble RBCs
Air Bubbles
•occur when the
specimen is placed
under a cover slip
t

87. Urinary Sediment Artifacts
Artifact Comments Appearance
Pollen grains
•Concentric
circles
•spheres with a cell wall
and occasional
concentric circles
Hair and fibers
from clothing
and diapers
•mistaken for casts
•usually much longer
and more refractile
Fecal Artifacts
•variety of
sizes and
shapes
•presence of a fistula
between the intestinal
and urinary tracts
•appear as plant and
meat fibers or as brown
amorphous material

88. END ☺