MICROSCOPIC EXAMINATION OF URINE: CASTS AND CRYSTALS

Question 1

Composed of Tamm-Horsfall (uromodulin) protein excreted by renal tubular epithelial cells

Answer 1

Casts

Question 2

When other urinary constituents are present they become enmeshed in the cast matrix or attached to the matrix

Answer 2

Casts

Question 3

Formed in the distal convoluted tubule and collecting ducts (wider casts)

Answer 3

Casts

Question 4

Reported as the number per low-power field

Answer 4

Casts

Question 5

Colorless

Answer 5

Hyaline

Question 6

Orange/red–containing RBCs

Answer 6

RBC

Question 7

WBCs in cast matrix

Answer 7

WBC

Question 8

RTE cells attached to cast matrix

Answer 8

Epithelial cell

Question 9

Bacteria attached to cast matrix

Answer 9

Granular

Question 10

Coarse or fine granules in the matrix

Answer 10

Granular

Question 11

Highly refractile, jagged edges and notches

Answer 11

Waxy

Question 12

Fat droplets and oval fat bodies attached to cast matrix

Answer 12

Fatty

Question 13

Wider than normal

Answer 13

Broad

Question 14

Mucus, fibers, increased light

Answer 14

Hyaline

Question 15

RBC clumps (look for cast matrix)

Answer 15

RBC

Question 16

WBC clumps (look for cast matrix)

Answer 16

WBC

Question 17

WBC casts

Answer 17

Epithelial cell

Question 18

Granular casts

Answer 18

Bacterial

Question 19

Clumps of small crystals, columnar RTE cells

Answer 19

Granular

Question 20

Fibers, fecal material

Answer 20

Waxy

Question 21

Fecal material

Answer 21

Fatty

Question 22

Fecal material, fibers

Answer 22

Broad

Question 23

Glomerulonephritis, pyelonephritis, congestive heart failure, stress, exercise

Answer 23

Hyaline

Question 24

Glomerulonephritis, strenuous exercise

Answer 24

RBC

Question 25

Pyelonephritis, acute interstitial nephritis

Answer 25

WBC

Question 26

Renal tubular damage

Answer 26

Epithelial cell

Question 27

Pyelonephritis

Answer 27

Bacterial

Question 28

Glomerulonephritis, pyelonephritis, stress, exercise

Answer 28

Granular

Question 29

Stasis of urine flow, chronic renal failure

Answer 29

Waxy

Question 30

Nephrotic syndrome, diabetes mellitus, crush injuries

Answer 30

Fatty

Question 31

Extreme urine stasis, renal failure

Answer 31

Broad

Question 32

Precipitation of urine solutes affected by

Answer 32

temperature, solute concentration, and pH

Question 33

are more abundant in refrigerated urine samples

Answer 33

Crystals

Question 34

Polarized microscopy aids in their identification

Answer 34

Crystals

Question 35

are found only in acidic or normal urine

Answer 35

Abnormal crystals

Question 36

Normal Crystals Seen in Acidic Urine

Answer 36

Uric acid crystals Amorphous urates Calcium oxalate crystals

Question 37

Normal Crystals Seen in Alkaline Urine

Answer 37

Triple phosphate crystals Amorphous phosphate crystals Calcium carbonate crystals Ammonium biurate crystals

Question 38

Abnormal Crystals

Answer 38

Cystine crystals Cholesterol crystals Tyrosine crystals Leucine crystals Bilirubin crystals Sulfonamide crystals Ampicillin crystals

Question 39

Yellow-brown, flat-sided rhombic plates, wedges, and rosettes

Answer 39

Uric acid crystals

Question 40

Sources of error ○ Cystine crystals (uric acid crystals polarize and cystine crystals do not polarize)

Answer 40

Uric acid crystals

Question 41

Clinical significance ○ Patients receiving chemotherapy ○ Lesch-Nyhan disease

Answer 41

Uric acid crystals

Question 42

Small spheres producing brick-dust (uroerythrin) or yellow-brown sediment

Answer 42

Amorphous urates

Question 43

May also be seen in alkaline urine

Answer 43

Calcium oxalate crystals

Question 44

The dihydrate form is envelope shaped; clumps in fresh urine may indicate renal calculi

Answer 44

Calcium oxalate crystals

Question 45

The monohydrate form is oval or dumbbell shaped; presence of this form indicates ethylene glycol (antifreeze) ingestion

Answer 45

Calcium oxalate crystals

Question 46

Coffin-lid shaped

Answer 46

Triple phosphate crystals

Question 47

Associated with a very high pH and bacteria found in old specimens

Answer 47

Triple phosphate crystals

Question 48

Produce a white precipitate after refrigeration

Answer 48

Amorphous phosphate crystals

Question 49

Dumbbell and spherical shapes

Answer 49

Calcium carbonate crystals

Question 50

Produce gas with acetic acid

Answer 50

Calcium carbonate crystals

Question 51

Yellow-brown thorny apple-shaped crystals

Answer 51

Ammonium biurate crystals

Question 52

Associated with old specimens with bacteria

Answer 52

Ammonium biurate crystals

Question 53

Hexagonal flat plates

Answer 53

Cystine crystals

Question 54

Clinical significance ○ Aninherited disorder that inhibits the reabsorption of cystine by the renal tubules (cystinuria); renal calculi form at an early age

Answer 54

Cystine crystals

Question 55

Rectangular plates with notched corners, highly birefringent under polarized light

Question 56

Seen in refrigerated urine and accompanied by fatty casts and oval fat bodies

Answer 56

Cholesterol crystals

Question 57

Clinical significance ○ Nephrotic syndrome

Answer 57

Cholesterol crystals

Question 58

Yellow needle-shaped forms in clusters or rosettes

Answer 58

Tyrosine crystals

Question 59

Clinical significance ○ Severe liver disease

Answer 59

Tyrosine crystals

Question 60

Yellow-brown spheres with concentric circles

Answer 60

Leucine crystals

Question 61

Seen in conjunction with tyrosine crystals

Answer 61

Leucine crystals

Question 62

Clinical significance ○ Severe liver disease

Answer 62

Leucine crystals

Question 63

Bright yellow clumped needles and granules

Answer 63

Bilirubin crystals

Question 64

Clinical significance ○ Liver damage often from viral infections that damage the renal tubules, preventing reabsorption of bilirubin

Answer 64

Bilirubin crystals

Question 65

Needle, rosette, and rhombic shapes

Answer 65

Sulfonamide crystals

Question 66

Clinical significance ○ Inadequately hydrated patients taking sulfonamide medications

Answer 66

Sulfonamide crystals

Question 67

Colorless needles that form clumps after refrigeration

Answer 67

Ampicillin crystals

Question 68

Clinical significance ○ Inadequately hydrated patients

Answer 68

Ampicillin crystals