Microscopic Examination of Urine - Urinary Crystals

Question 1

Crystals frequently found in the urine are rarely of clinical significance. True or False?

Answer 1

True

Question 2

Appearance of urinary crystals

Answer 2

True geometrically formed structures or as amorphous material

Question 3

The primary reason for the identification of urinary crystals

Answer 3

To detect the presence of the relatively few abnormal types that may represent such disorders

Question 4

Manner of reporting for crystals

Answer 4

Rare, few, moderate, or many per hpf

Question 5

How does urinary crystal forms?

Answer 5

Precipitation of urine solutes

Question 6

Precipitation is subject to changes in

Answer 6

Temperature
Solute concentration
pH

Question 7

Solutes precipitate more readily at high temperatures. True or False?

Answer 7

False; low temperature

Question 8

As the concentration of urinary solutes increases, their ability to remain in solution decreases. True or False?

Answer 8

True

Question 9

How does pH of the specimen aid in the identification of crystals?

Answer 9

It determines the type of chemicals precipitated

Question 10

Organic and iatrogenic compounds crystallize more easily in acidic or alkaline pH?

Answer 10

Acidic

Question 11

Inorganic salts are less soluble in

Answer 11

Neutral and alkaline solutions

Question 12

Crystal that precipitates in both acidic and neutral urine

Answer 12

Calcium oxalate

Question 13

All abnormal crystals are found in alkaline urine. True or False?

Answer 13

False; acidic urine

Question 14

Microscopy technique that aids in the identification of crystals

Answer 14

Polarized microscopy

Question 15

The geometric shape of a crystal determines its birefringence. True or False?

Answer 15

True

Question 16

Slower crystallization produces smaller crystals. True or False?

Answer 16

False; larger crystals

Question 17

Duration of crystallization alters the basic structure of crystals. True or False?

Answer 17

False; basic structure remains the same

Question 18

Amorphous urates in refrigerated specimens may dissolve if the specimen is warmed. True or False?

Answer 18

True

Question 19

Amorphous phosphates require acetic acid to dissolve. True or False?

Answer 19

True

Question 20

The most common crystals seen in acidic urine

Answer 20

Urates

Consisting of amorphous urates, uric acid, acid urates, and sodium urates

Question 21

Appearance of urates crystals

Answer 21

Yellow to reddish brown

Question 22

The only normal crystals found in acidic urine that appear colored

Answer 22

Urates

Question 23

Amorphous urates are similar to what casts?

Answer 23

Granular casts

Question 24

Amorphous urates are frequently encountered in

Answer 24

Specimens that have been refrigerated and produce a very characteristic pink sediment due to accumulation of uroerythrin

Question 25

Amorphous urates are found in acidic urine with a pH of

Answer 25

>5.5

Question 26

Amorphous urates are soluble in

Answer 26

Alkali and heat

Question 27

Seen in a variety of shapes, including rhombic, four-sided flat plates (whetstones), wedges, and rosettes

Answer 27

Uric acid

Question 28

They usually appear yellow-brown, but may be colorless and have a six-sided shape, similar to cystine crystals

Answer 28

Uric acid

Question 29

How to distinguish uric acid from cystine crystals?

Answer 29

Uric acid is highly birefringent under polarize light

Question 30

Increased amount of uric acid is associated with

Answer 30

Increased levels of purines and nucleic acids

Question 31

Increased amount of uric acid in patients is associated with

Answer 31

Leukemia who are receiving chemotherapy Lesch-Nyhan syndrome Gout

Question 32

Uric acid is soluble in

Answer 32

Alkali

Question 33

Appear as larger granules and may have spicules similar to the ammonium biurate crystals seen in alkaline urine

Answer 33

Acid urates

Question 34

Are needle-shaped and are seen in synovial fluid during episodes of gout, but may also appear in the urine

Answer 34

Sodium urates

Question 35

Frequently seen in acidic urine, but they can be found in neutral urine and even rarely in alkaline urine

Answer 35

Calcium oxalate

Question 36

2 forms of calcium oxalate

Answer 36

Dihydrate form (Weddellite) Monohydrate form (Whewellite)

Question 37

Most common form (calcium oxalate) and is easily recognized as a colorless, octahedral envelope or as two pyramids joined at their bases

Answer 37

Dihydrate form (Weddellite)

Question 38

Oval/dumbbell/hourglass shape (calcium oxalate) and less frequently seen

Answer 38

Monohydrate form (Whewellite)

Question 39

How to distinguish monohydrate calcium oxalate from nonpolarizing RBCs?

Answer 39

Monohydrate forms are birefringent under polarized light

Question 40

Foods associated with calcium oxalate

Answer 40

Foods high in oxalic acid, such as tomatoes and asparagus, and ascorbic acid

Question 41

Primary pathologic significance of calcium oxalate

Answer 41

Presence of the monohydrate form in cases of ethylene glycol (antifreeze) poisoning

Question 42

Calcium oxalate is soluble in

Answer 42

Dilute HCl

Question 43

Majority of renal calculi are composed of

Answer 43

Calcium oxalate

Question 44

The finding of clumps of calcium oxalate crystals in fresh urine may be related to

Answer 44

Formation of renal calculi

Question 45

The majority of the crystals seen in alkaline urine

Answer 45

Phosphates include amorphous phosphate, triple phosphate, calcium phosphate, calcium carbonate, and ammonium biurate

Question 46

Granular in appearance, similar to amorphous urates

Answer 46

Amorphous phosphates

Question 47

Appearance of amorphous phosphate following specimen refrigeration

Answer 47

White precipitate that does not dissolve on warming

Question 48

How to differentiate amorphous urates from amorphous phosphates?

Answer 48

Color of the sediment and the urine pH

Question 49

Amorphous phosphate is soluble in

Answer 49

Dilute acetic acid

Question 50

Easily identified by their prism shape that frequently resembles a “coffin lid”

Answer 50

Triple phosphate/Ammonium magnesium phosphate/struvite crystals

Question 51

Shape of triple phosphate crystals

Answer 51

Feathery appearance when they disintegrate, Fern-leaf shape, sheets or flake

Question 52

Appearance of triple phosphate crystals under polarized light

Answer 52

Birefringent

Question 53

Crystal often seen in highly alkaline urine associated with the presence of urea-splitting bacteria

Answer 53

Triple phosphate

Question 54

Triple phosphate is soluble in

Answer 54

Dilute acetic acid

Question 55

Crystal that appear as colorless, flat rectangular plates or thin prisms often in rosette formations

Answer 55

Calcium phosphate/Apatite crystals

Question 56

How to differentiate calcium phosphate from sulfonamide crystals?

Answer 56

Calcium phosphate crystals dissolve in dilute acetic acid and sulfonamides do not

Question 57

Crystals that are small and colorless, with dumbbell or spherical shapes

Answer 57

Calcium carbonate

Question 58

How to differentiate calcium carbonate from amorphous materials?

Answer 58

Formation of gas after the addition of acetic acid

Question 59

Crystals frequently described as “thorny apples” because of their appearance as spicule-covered spheres

Answer 59

Ammonium biurate

Question 60

Crystals that are almost always encountered in old specimens

Answer 60

Ammonium biurate

Question 61

Ammonium biurate is soluble in

Answer 61

Acetic acid with heat

Question 62

Abnormal urine crystals are found in

Answer 62

Acidic urine or rarely in neutral urine

Question 63

Crystals found in the urine of persons who inherit a metabolic disorder that prevents reabsorption of cystine by the renal tubules (cystinuria)

Answer 63

Cystine crystals

Question 64

Appearance of cystine crystals

Answer 64

Colorless, hexagonal plates and may be thick or thin

Question 65

How to differentiate uric acid crystals from cystine crystals?

Answer 65

Uric acid crystals are very birefringent under polarized microscopy, whereas only thick cystine crystals have polarizing capability

Question 66

Test for the positive confirmation of cystine crystals

Answer 66

Cyanide-nitroprusside test

Question 67

Cystine crystal is soluble in

Answer 67

Acetic ammonia, dilute HCl

Question 68

Crystal resembling a rectangular plate with a notch in one or more corners (staircase pattern)

Answer 68

Cholesterol crystals

Question 69

Crystal with most characteristic appearance

Answer 69

Cholesterol crystal

Question 70

Cholesterol crystals are soluble in

Answer 70

Chloroform

Question 71

Crystals that have a very similar appearance to cholesterol crystals and also are highly birefringent

Answer 71

Radiographic dye crystals

Question 72

How to differentiate cholesterol crystals from radiographic dye crystals?

Answer 72

Comparison of the other urinalysis results Patient history

Question 73

Cholesterol crystals should be accompanied by

Answer 73

Other lipid elements and heavy proteinuria

Question 74

Crystals associated with liver disease

Answer 74

Tyrosine Leucine Bilirubin

Question 75

Crystals appear as fine colorless to yellow needles that frequently form clumps or rosettes

Answer 75

Tyrosine crystals

Question 76

Tyrosine crystals are usually seen in conjunction with bilirubin crystals in specimens with positive chemical test results for leucine. True or False?

Answer 76

False; leucine crystals, positive chemical test results for bilirubin

Question 77

Tyrosine crystal is soluble in

Answer 77

Alkali or heat

Question 78

Yellow-brown spheres that demonstrate concentric circles and radial striations

Answer 78

Leucine

Question 79

Leucine crystals when present, should be accompanied by

Answer 79

Tyrosine crystals

Question 80

Leucine crystal is soluble in

Answer 80

Hot alkali or alcohol

Question 81

Crystals that appear as clumped needles or granules with the characteristic bright yellow color of bilirubin

Answer 81

Bilirubin crystals

Question 82

The presence of bilirubin crystals gives positive result for bilirubin when using reagent strip. True or False?

Answer 82

True

Question 83

Bilirubin crystal is soluble in

Answer 83

Acetic acid, HCl, NaOH, ether, chloroform, and alkali

Question 84

Primary cause of sulfonamide crystallization

Answer 84

Inadequate patient hydration

Question 85

The appearance of sulfonamide crystals in fresh urine can suggest the possibility of

Answer 85

Tubular damage

Question 86

Most frequently encountered shapes of sulfonamide crystals

Answer 86

Needles, rhombics, whetstones, sheaves of wheat, and rosettes with colors ranging from colorless to yellow-brown

Question 87

Sulfonamide crystals is soluble in

Answer 87

Acetone

Question 88

Crystal that appear as colorless needles that tend to form bundles following refrigeration

Answer 88

Ampicillin crystals

Question 89

Ampicillin crystals are seen in

Answer 89

High doses of penicillin compound without adequate hydration