Crystals
Urinary Crystals
• Most crystals form after urine sits
– urinary solutes precipitate(ppt) out of solution
• Clinical Significance
– MOST are clinically INsignificant
– Generally clinically significant crystals are present
on freshly voided urine (body temp.)
– Crystal composition may imply urinary calculi
2
Urinary Crystals
• Clinical Significance Continued
– May indicate metabolic disorder
• Cystinuria - inherited metabolic condition
– Crystals of some drugs may precipitate(ppt)
out, especially in high doses
• Sulfonamides
3
• Formation
– crystals ppt out of solution when the
concentration in solution is greater than the
solubility threshold for that solute
– Factors that affect crystal formation
• pH, solute concentration, filtrate volume passing
through kidneys
4
• Classification
– Normal and Abnormal
• Normal Acidic crystals
• Normal Alkaline crystals
• Abnormal crystals - metabolic origin or iatrogenic origin
– Morphology
• Based on pH
• Generally reported based on morphology alone
5
6
7
Normal Acidic Crystals
• Amorphous urates
– amorphous:
– salt of uric acid (Na, Mg, Ca or K)
– yellow/red to red/brown
• Uric Acid
– along with amorphous urates, most common
– pH <6.0
8
Uric Acid
Acid urine
Yellowish Brown
Ovals with pointed
Ends
9
Uric Acid
Birefringence
under
polarized light
10
Uric Acid
Sometimes
associated with
gout
11
Uric Acid Rosette Form
Many Forms
“Great
Imposters”
12
Normal Acidic Crystals
• Calcium oxalate
– may also been seen in neutral or alkaline urine
– dihydrate form is easily recognized
13
Calcium Oxalate
• Common
• pH acid or neutral
• Envelope or dumb
bell shaped
• Oval May be
mistaken for RBC
• Ca Ox soluble in
HCl Insoluble in
acetic acid
• RBC lyse in acetic
acid
14
Calcium Oxalate and Epi
15
Calcium Oxalate
16
Calcium oxalate dihydrate and
monohydrate (dumbbell and ring forms)
- x400 magnification.
17
Calcium Oxalate
18
Amorphous Urates
Brown or
colorless
granules
Na or K
Sediment in
spin down
tube may
have brick
red color
19
Amorphous Phosphates
• Ca or Mg
• Found in Basic
urine
• Dissolves in
Acetic Acid
20
Normal Alkaline Crystals
•
•
•
•
•
Amorphous Phosphates
Triple Phosphate (ammonium magnesium)
Ammonium Biurate
Calcium Phosphate Crystals
Calcium Carbonate
21
Triple Phosphate
Coffin Lid
22
Triple Phosphate
AKA Ammonium
Magnesium Phosphate
Found in Basic or
Neutral urine
Soluble in Acetic Acid
23
Calcium Phosphate Crystals
Alkaline urine
Irregular plates
“Sheets of Ice”
Rosettes
Associated with Cystitis
and Urine retention
24
Calcium Carbonate Crystals
Alkaline urine
Spheres or Dumbbell forms
Birefringent
25
Ammonium Biurate
– Rarely seen in freshly
voided urine - common
in old specimens
– Dark yellow or brown
26
Calcium Carbonate
• Rhombohedral
form
27
Calcium Carbonate
• Dumbbell form
28
Abnormal Crystals
• All are found in acidic urine
• Indicate pathologic condition
29
Tyrosine
Acid pH
Needle shaped
fine and silky
appearance
Liver disease due
to hepatitis,
hepatocellular
poisons
Leukemia's
Typhoid fever and
smallpox
30
Leucine
Acid pH
Spheres, Yellowbrown concentric
rings
Birefringence
Pseudo Maltese
Cross
Maple syrup
disease
Liver Disease
31
Acid pH
Cystine
Thin colorless
hexagonal plates
Birefringent in
polarized light
Hereditary
metabolic
disorders
involving renal
transport of
various amino
acieds
32
Cystine
33
Cystine
34
Cholesterol
Acid Urine
Regular or irregular
plate with Notched
corner
Birefringent under
polarized light
Various renal
diseases
Nephrotic Syndrome
or other condition
where there is a
deposition of lipids
in Kidney
35
Cholesterol
36
Fiber
37
Bilirubin Crystals
• Acidic Urine
• Pigmented
yellowish Brown
Granules
• Pathologic appear
in a wide variety of
hepatobiliary and
hematopoietic
diseases
38
Bilirubin Crystals
39
Thank you
40