Dr Aarthi KB MD Pathology 1st Year

1. Microscopic examination
of urine
-Dr Aarthi KB

2. Sample collection
 Mid-stream fresh first morning sample
because it is well concentrated.
 Urine examination to be done immediately
or within 2 hours of sample collection

3. Method of examination
 10-15 ml urine sample centrifuged for 5-10
min at 2000-3000 rpm.
 Supernatant is poured off.
 Tube tapped at bottom to resuspend the
sediment.
 A drop is placed on the slide and covered
with a cover slip
 Examined under microscope in high
power(40x)

5. Classification
 Organised
 Unorganised

6. Organised substances

7. Unorganised substances
 Crystalline
 Amorphous material

10. Cells
Erythrocytes:
 Pale biconcave discs about 7 mum in diameter.
 Unfresh specimen-shadow cells(faint and
colourless)
 In hypertonic urine-crenated
 In dilute urine-ghost cells
 0-2/hpf is normal

13.  Dysmorphic red cells:
RBCs with cellular protrusions or fragmentations
>80% dysmorphic red cells suggests glomerular pathology.

14. Renal diseases:
Glomerulonephritis
Lupus nephritis
Tb
Tumor
Renal vein thrombosis
Hydronephrosis
Polycystic kidney disease

15. Lower urinary tract diseases:
Acute and chronic infection
Calculus
Tumour
Hemorrhagic cytitis

16. Drugs:
Sulphonamides
Anticonvulsants
Salicylates
methenamine

17. Extra renal diseases:
 Acute appendicitis
 Malaria
 Sub Acute Bacterial Endocarditis
 Pan Arteriosus Nodosa

18.  Scurvy
 Tumours of colon rectum pelvis
 Salphingitis
 Diverticulitis

19. WBC
Neutrophils:
 Granular spheres,12mum in dia,multilobed nuclei
 Clumps-infections
 Many white cells in urine is pyuria.
 In hypotonic urine white cells are swollen,granules are
highly refractile and show brownian movement called
glitter cells.

21.  <5/hpf-normal
 >10/hpf or presence of clumps-UTI
 Increased pus cells seen in
1. Fever
2. Pyelonephritis
3. Tubulointerstitial nephritis
4. Renal transplant rejection
White cells+casts-renal infection(pyelonephritis)

22. Eosinophils
 >1%-acute interstitial nephritis
 Appreciated in Wright’s staining.
 Small lymphocytes and histiocytes-renal transplant
rejection and chronic inflammation

24. Epithelial cells
Squamous epithelial cells:
 Lines lower urethra and vagina
 Most frequent epithelial cells in normal urine and
least significant
 Cells are large and flat with abundant cytoplasm
and small round central nuclei.
 Large number of cells indicate contamination by
vaginal fluid.

26. Transitional (urothelial) cells:
 Lines renal pelvis, ureters, urinary bladder and
upper urethra.
 Smaller than squamous cells.
 Round or pear shaped (caudate cells) with centrally
located nucleus
 Large clumps or sheets seen in transitional cell
carcinoma.

29. Renal tubular epithelial cells:
 Similar in size as white blood cells
 Polyhedral,have granular cytoplasm
 Large eccentric refractile nucleus seen.

30.  Increase number seen in tubular damage:
1. Acute tubular necrosis
2. Pyelonephritis
3. Viral infections of kidney
4. Salicylate poisoning
5. Allograft rejection

33. Oval Fat bodies:
 Are tubular cells that have absorbed lipoproteins from
glomeruli
 Cholesterol - exhibit maltese cross under polarised light
 Triglyceride- Oil red O or Sudan III is required.
 Presence of these along with proteinuria=nephrotic
syndrome.

35. Telescoped urinary sediment
 Sediment consists of rbc,wbc,oval fat bodies and all
types of casts.
 Seen in
1. Lupus nephritis
2. Malignant hypertension
3. Rapidly progressing Glomerulonephritis
4. Diabetic glomerulonephritis

36. Casts
 Formed elements of urine that have kidney as their
origin
 Tamm-horsfall protein-secreted by ascending loop
of henle.
 All are hyaline. various types formed when
different elements get deposited on the hyaline
material.

38. Types
 Cellular-
1. RBC,
2. WBC,
3. Renal tubular epithelial cells

39.  Non-cellular:
1. Hyaline,
2. Granular,
3. waxy,
4. fatty

40. Non-cellular casts
Hyaline casts:
 Homogenous,colourless,refractile
 Cylindrical with parallel sides and blunt ends
 Increased numbers-cylinduria
 Composition-Tamm horsfall protein

41.  Increased numbers seen in
1. Glomerular nephritis
2. Chronic pyelonephritis
3. Congestive heart failure
4. Transiently increased in-
exercise,fever,heat exposure

43. Granular casts:
 Presence of cellular debri in a cast makes it granular in
appearance
 Cylindrical structures with coarse and fine
granules(degenerated renal tubular epithelial cells)

44.  Seen in:
1. nephrotic syndrome,
2. Lead toxicity
3. acute glomerulonephritis,
4. pyelonephritis

45. Granular casts

46. Waxy casts:
 Formed when hyaline casts remain in tubules for a
prolonged period
 Homogenous smooth glassy appearance cracked or
serrated margins
 Light yellow in colour
 Seen in End stage renal failure.

48. Fatty casts:
 Cylindrical structures filled with highly refractile fat
globules
 Seen in nephrotic syndrome

50. Broad casts:
 Form in dilated distal tubules
 Seen in chronic renal failure and severe tubular
obstruction
 Waxy and broad casts-worst prognosis

51. Cellular casts
 Casts contains at least three cells in matrix
Red cell casts:
 Cylindrical structures,appear brown due to hemoglobin
pigmentation
 Seen in acute glomerulonephritis
Ig A nephropathy
lupus nephritis etc.

53. White cell casts:
 Cylindrical structures with white blood cells embedded
in Tamm-horsfall protein.
 Refractile and exhibit granules
 Multi-lobed nucleus

54.  Seen in
1. pyelonephritis,
2. interstitial nephritis,
3. lupus nephritis.

56. Renal tubular epithelial cell casts:
 Singular rounded nuclei.
 Seen in acute tubular necrosis,
viral renal disease,
heavy metal poisoning,
acute allograft rejection.
 Even occasional finding is significant.

59. Crystals
 Formed by precipitation of urinary salts due to
alterations in pH,temperature and concentration.
 They can be
1. Normal
2. Abnormal

60. Normal crystals
 Crystals in acid urine:
a. Uric acid crystal:
Variable in shape-diamond,barrel,plate-like and hexagonal
Yellow or red-brown in colour
Increased number-gout and leukemia

62. b.Calcium oxalate crystals:
 Colourless,refractile and enveloped-shaped.
 Ingestion of tomatoes, spinach, cabbage, asparagus may
cause increase in number.
 Large number seen in ethylene glycol poisoing

65. c.Amorphous Urates:
 Urate crystals of potassium,magnesium or calcium in
acid urine
 Yellow fine granules

67.  Crystals in alkaline urine:
1.Calcium carbonate crystals:
 Small colourless and in pairs.
 Gives bubbles when they dissolve
 Round in shape with radial striations.

69. 2.Phosphate:
 Occur as crystals or as amorphous deposits
o Triple phosphates(Ammonium magnesium phosphates):
 Struvite stones.
 Coffin lid appearance
 Seen in UTI patients caused due to Proteus mirabilis.

71. o Calcium hydrogen phosphate(Stellar Phosphate)-Brushite
stones
 Colourless and variable shapes seen.
 Star,plates,prisms

72. 3.Ammonium Urate crystals:
 Appear as cactus like thornapple crystals
 Yellow-brown

74. Abnormal crystals
 Occur in acidic pH
 Additional chemical tests are to be done for
confirmation.
1.Cystine crystals:
 Colourless,hexagonal,
 Seen in cystinuria
 Associated with formation of cysteine stones.

76. 2.Cholesterol crystals:
 Colourless,refractile,rectangular plates with notched
corners.
 Seen in nephrotic syndrome and hypercholesterolemia

77. 3.Bilirubin crystals:
 Small brown crystals
 Square,bead-like or fine needle in shape
 Seen in severe obstructive liver diseases

78. 4.Leucine crystals:
 Refractile,yellow-brown sphere with radial or concentric
striations
 Seen with tyrosine crystals in severe liver
disease(cirrhosis)

79. 5.Tyrosine crystals:
 Clusters or fine delicate,
 Colourless or yellow needles
 Seen in liver disease,tyrosinemia.

80. 6.Sulfonamide crystals:
 Seen as sheaves of needles.
 Occur following sulphonamide therapy.

81. Abnormal cells and formed elements
 Tumour cells:
 Exfoliated Malignant cells
 Myeloma cells

82.  Bacteria:
 Gram stain bacteria more than 100000/microlitre-
significant bacteriuria.

83.  Fungi:
 Yeasts commonly seen in UTI of diabetic patients
 Confused with RBC

84.  Parasite:
 Trichomonas vaginalis may occur due to
 Vaginal contamination
 Urethral and bladder infection
 Identified by its motility.

86. Contaminants and artifacts
 Muscle fibres
 Pollen grains
 Starch granules
 Spermatozoa