1. Crystals

2. 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

3. 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

4. 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

5. Classification Normal and Abnormal Morphology Normal Acidic crystals
Normal Alkaline crystals
Abnormal crystals - metabolic origin or iatrogenic origin
Morphology
Based on pH
Generally reported based on morphology alone

8. 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

9. Uric Acid Acid urine Yellowish Brown Ovals with pointed Ends

10. Uric Acid Birefringence under polarized light Acid urine
Yellowish Brown
Ovals with pointed Ends
Birefringence under polarized light

11. Uric Acid Sometimes associated with gout Acid urine Yellowish Brown
Ovals with pointed Ends

12. Uric Acid Rosette Form
Many Forms
“Great Imposters”

13. Normal Acidic Crystals
Calcium oxalate
may also been seen in neutral or alkaline urine
dihydrate form is easily recognized

14. 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
Tomatoes

15. Calcium Oxalate and Epi

16. Calcium Oxalate

17. Calcium oxalate dihydrate and monohydrate (dumbbell and ring forms) - x400 magnification.

18. Calcium Oxalate

19. Amorphous Urates Brown or colorless granules Na or K
Sediment in spin down tube may have brick red color
Brown or colorless granules
Na or K
Sediment in spin down tube may have brick red color

20. Amorphous Phosphates Ca or Mg Found in Basic urine
Dissolves in Acetic Acid

21. Normal Alkaline Crystals
Amorphous Phosphates
Triple Phosphate (ammonium magnesium)
Ammonium Biurate
Calcium Phosphate Crystals
Calcium Carbonate

22. Triple Phosphate
Coffin Lid
Looks like a Coffin Lid

23. Triple Phosphate AKA Ammonium Magnesium Phosphate
Found in Basic or Neutral urine
Soluble in Acetic Acid

24. Calcium Phosphate Crystals
Alkaline urine
Irregular plates
“Sheets of Ice”
Rosettes
Associated with Cystitis and Urine retention

25. Calcium Carbonate Crystals
Alkaline urine
Spheres or Dumb-bell forms
Birefringent

26. Ammonium Biurate
Rarely seen in freshly voided urine - common in old specimens
Dark yellow or brown

27. Calcium Carbonate
Rhombohedral form

28. Calcium Carbonate
Dumbbell form

29. Abnormal Crystals All are found in acidic urine
Indicate pathologic condition

30. Tyrosine Acid pH Needle shaped fine and silky appearance
Liver disease due to hepatitis, hepatocellular poisons
Leukemia's Typhoid fever and smallpox

31. Leucine Acid pH Spheres, Yellow-brown concentric rings Birefringence
Pseudo Maltese Cross
Maple syrup disease
Liver Disease

32. Cystine Acid pH Thin colorless hexagonal plates
Birefringent in polarized light
Hereditary metabolic disorders involving renal transport of various amino acieds

33. Cystine

34. Cystine

35. 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
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 depositio of lipids in Kidney

36. Cholesterol

37. Fiber

38. Bilirubin Crystals Acidic Urine Pigmented yellowish Brown Granules
Pathologic appear in a wide variety of hepatobiliary and hematopoietic diseases

39. Bilirubin Crystals

40. Thank you