Urine - Sediment Exam Flashcards
Urine Amount
- Minimum of 6 mL needed
- 12-15 mL best
- If below 6 mL, note on report
Normal Cell Amounts
Urine Sediment
- RBCs = <2-3 cells / HPF
- WBCs = 0-1 cells / HPF
- Epithelial Cells = occasional / HPF
RBC Appearance / Changes
Urine Sediment
Appearance changes based on pH, SG, and time elapsed
* crenation = high SG
* swell or lyse = low SG or alkaline urine
* can be confused with fat or yeast
RBCs in Urine Sediment
WBC
Urine Sediment
- Most are neutrophils
- Larger than RBCs, but smaller than renal epithelial cells
- Culture if excessive seen, even without bacteria
WBC Appearance / Changes
Urine Sediment
Changes based on SG
* shrink = high SG
* swell = low SG
WBC in Urine Sediment
Epithelial Cells
Normal Urine Sediment
- Normal = few (older cells sloughing off)
- Increased = inflammation
Types of Epithelial Cells
- Squamous
- Transitional
- Renal
Squamous Epithelial Cells
- Origin of distal urethra, vagina, vulva, prepuce
- Usually not significant
- Collected in voided samples
Squamous Epithelial Cell Appearance
- Large, flat, thin cels
- Straight edges with distinct corners
- Small, round nucleus
Squamous Epithelial Cells
Transitional Epithelial Cells
- Origin in bladder, ureters, renal pelvis, proximal urethra
- Normal = low (0-1 / HPF)
- Increased = cystitis or pyelonephritis / catheterization
Transitional Epithelial Cells Appearance
- Round or pear-shaped
- Granular with small nuclei
Clumping Transitional Epithelial Cells
- Indicative of Transitional Cell Carcinoma (especially if no WBC)
- Neoplastic
- Carcinoma can have cells be different size
- Can be caused by catheterization
- Chemotherapy and radiation needed for treatment
Transitional Epithelial Cells
Renal Epithelial Cells
- Origin in renal tubules
- Normal = rare, 0-1 / HPF
- Increased = Kidney disease
Renal Epithelial Cell Appearance
- Smallest
- Slightly larger than WBCs
- Round with large nucleus
- Non-granular to finely granular
Renal Epithelial Cells
Casts
Urine Sediment
- Form in lumen or distal/collecting tubules
- Localize injury to kidney
- Any seen indicate abnormality - implies some degree of renal damage
- Dissolve in alkaline urine
- Number is not indicative of renal disease severity
Casts Appearance
General
- Cylindrical structures
- Parallel sides
- Width is same as tubule lumen
Hyaline Casts
- Composed of mucoprotein
- Seen with mild renal injury and glomerular leakage
- Easier to identify with staining
Hyaline Casts Appearance
- Clear, colorless, and somewhat transparent
- Rounded end
Hyaline Casts
Granular Casts
- Older epithelial cell casts that degenerated and can no longer be identified as individual cells
- Coarsely = early stage
- Finely = late stage (form waxy casts)
- Most common type
Granular Casts
Cellular Casts
May be red, white, or epithelial cell in composition
* red = indicate renal hemorrhage or inflammation
* white = indicate renal inflammation
* epithelial = indicate acute tubular degeneration
Increased = severe kidney disease or acute nephritis
Cellular Casts
Waxy Casts
- Indicate chronic tubular degeneration
- Must be distinguished from hyaline casts
- Essentially means kidney has shut down
Waxy Cast Appearance
Wide with square ends when compared to hyaline casts
Waxy Casts
Progression of Casts
Not as Severe - Severe
- Hyaline
- Cellular
- Granular
- Waxy
Urinary Crystals
- Form due to their elements secreted into urine by normal renal activity
- Type depends on pH, concentration, temp, solubility of elements
Struvite Crystals
- Also known as triple phosphate (magnesium ammonium phosphate)
- Form in alkaline urine
- “Coffin lids”
Struvite Crystals
Calcium Oxalate Crystals
- Can be Dihydrate or Monohydrate
- Form in acidic or neutral urine
Dihydrate Calcium Oxalate Crystals
- Small square crystals
- Contain an “X” through center
Monohydrate Calcium Oxalate Crystals
- Small and dumbbell-shaped or elongated
- Pointed at end
- Seen with ethylene glycol toxicity
Dihydrate Calcium Oxalate Crystals
Monohydrate Calcium Oxalate Crystals
Cystine Crystals
- 6-sided, colorless, and thin
- Renal tubule dysfunction
- Inherited metabolic defect
Cystine Crystals
Ammonium Biurate Crystals
- Round with long irregular spikes
- Brown color
- See with any pH
- Common with liver disease
Ammonium Biurate Crystals
Uric Acid Crystals
- Usually diamond or rhomboid shape
- Yellow or yellow-brown
- Uncommon, except for in Dalmatians
Uric Acid Crystals
Amorphous Crystalline Material
Phosphate
* alkaline urine
Urate
* acidic urine
Both contain granular precipitates
Amorphous Crystals
Leucine Crystals
- Wheel or pin-cushion shaped
- See with liver disease
Leucine Crystals
Tyrosine Crystals
- Dark with needle-like projections
- See with liver disease
Tyrosine Crystals
Pathological Crystals
- Cystine
- Tryocine
- Leucine
Bacteria
Only observed with contamination
* Cocci = round shape
* Bacilli = rod shape
* Quantitate on Low Power Field
Parasites
Urinary parasites or result of fecal contamination
* bladder worm = p. plica
* kidney worm = d. renale
Bladder worm (p. plica)
Kidney Worm (d. renale)
Mucus Threads
- Twisted ribbon
- Confused with casts - not well delineated edges
- Indicate urethral irritation or genital secretion contamination
Mucus Thread
