Microscopic Examination of Urine Flashcards
What are the nonpathological causes of finding RBCs in urine?
● Strenuous exercise
● Menstrual contamination
What are the pathological clinical significance of finding RBCs in urine? State atleast three
● Hematuria
●Glomerulonephritis
● Renal calculi Malignancy
● Vascular injury within the genitourinary tract
In a hypotonic urine, RBCs appear?
Ghost cells
In a hypertonic urine, RBCs appear?
Crenated
Describe the appearance of a RBC
Biconcave,
anucleate discs , and 7 μm in
diameter
In a glomerular membrane damage, RBCs appear?
Dsymorphic
What are the sources of identification error of RBCs
- Yeast cells
- Oil droplets
- Air bubbles
Reporting for microscopic RBCs:
Average number per 10 HPFS
Complete urinalysis
correlations of RBCs
Reagent strip blood reaction
What is the normal value of RBCs in urine?
0-2/HPF
These are larger than RBCs, measuring an average of about
12 mm in diameter
WBCs
The predominant WBC found in the urine sediment is:
Neutrophil
In a hypotonic urine, WBCs appear as?
Glitter cells
What are the sources of identification error of WBCs
Renal tubular epithelial cells
Describe the appearance of WBCs
● Non-nucleated biconcave disks
● Larger than RBCs, an average of about 12 mm in diameter
● Granulated, multilobed neutrophils
● Glitter cells in hypotonic urine
● Mononuclear cells with abundant cytoplasm
What are the clinical significance of finding WBCs (above normal values) in urine?
● Pyelonephritis
● Cystitis
● Prostatitis
● Urethritis
● Glomerulonephritis
● Lupus erythematosus
● Interstitial nephritis
● Tumors
Neutrophils lyse rapidly in __________ urine and begin to lose nuclear detail.
dilute alkaline
What is the possible non pathologic significance of finding WBCs in urine?
Glitter cells
The presence of urinary ______ is primarily associated
with drug-induced interstitial nephritis
eosinophils
Reporting for microscopic WBCs:
Average number per 10 hpfs
Complete urinalysis correlations of WBCs
- Leukocyte esterase
- Nitrite
- Specific gravity
- pH
Describe the appearance of a squamous epithelial cell
Largest cells in the sediment with abundant, irregular cytoplasm and prominent nuclei
Reporting for squamous epithelial cells in urine:
Rare, few, moderate, or many per LPF
Describe the appearance of transitional cells
Spherical, polyhedral, or caudate
with centrally located
nucleus
Reporting for transitional cells in urine:
Rare, few, moderate, or many per HPF
Describe the appearance of RTE cells
Rectangular, colomnar, round, oval or cuboidal with an eccentric nucleus
Reporting for RTE cells in urine:
Average number per 10 HPFs
Describe the appearance of oval fat bodies
Highly refractile RTE cells
Reporting for oval fat bodies in urine:
Average number per HPF
It is the most clinically significant of the epithelial cells
RTE cells
What is the clinical significance of finding squamous epithelial cells (above the normal values) in urine?
- Clue cells (indicative of vaginal infection by Gardnerelia vaginalis)
What are the clinical significance of finding RTE cells in urine?
- Tubular necrosis
- Glomerular disorders
- Severe tubular injury with basement membrane disruption
- Salicylate poisoning
What is the clinical significane of finding transitional epithelial cells in urine?
Malignancy or viral infection
Decribe the appearance of bacteria in urine
Small spherical and rod-shaped
structures
Reporting of bacteria in urine:
Few, moderate, or many per HPF (the presence of WBCs may
be required)
It appears as small, oval, refractile structures with buds and/or mycelia
Yeast
Reporting of yeast in urine:
Rare, few, moderate, or many per HPF (the presence of WBCs may be required)
It appears pear-shaped, motile, flagellated
Trichomonas
Reporting of Trichomonas in urine:
Rare, few, moderate, or many per HPF
It appears as single or clumped threads with a low refractive index
Mucus
Reporting of mucus in urine:
Rare, few, moderate, or many per LPF
These structures are reported as rare, few, moderate, or many per HPF
- Bacteria
- Yeast
- Trichomonas
- Crystals
(mucus is reported per LPF)
Casts are formed in which parts of the kidney nephron?
- Lumen of the distal convoluted tubule
- collecting ducts
Why should casts be observed under subdued light?
Because cast matrix has a low refractive index
Reporting casts in urine:
Average number per 10 LPFs
What is the major constituent of casts?
uromodulin
(other protiens present are albumin and immunoglobulins)
The presence of urinary casts is termed:
cylindruria
Normal values of hyaline cast in urine
0-2 per LPF
What are th nonpathological causes of finding increased numbers of hyaline cast in urine?
- Strenous exercise
- Dehydration
- Heat exposure
- Emotional stress
What are the pathological causes of finding increased numbers of hyaline cast in urine?
- Acute glomerulonephritis
- Pyelonephritis
- Chronic renal disease
- Congestive heart failure
This stain produces a pink color in hyaline casts
Sternheimer-Malbin stain
Increased visualization of (hyaline) casts can be obtained by using what type of a microscope?
Phase microscope
What is the specific significance of finding RBC cast in urine?
Bleeding within the nephron; glomerulonephritis
Nonpathological cause of RBC cast in urine
Strenuous contact sports
The appearance of this cast in the urine signifies infection or inflammation within the nephron
WBC cast
Clinical significance of WBC casts in urine are?
- Pyelonephritis
- Acute interstitial nephritis
Describe the appearance of a RBC cast in urine
Orange-red color, cast matrix containing RBCs
Describe the appearance of Hyaline casts in urine
- Colorless, homogenous matrix
This cast contains WBCs in its matrix
WBC cast
It appears as a bacilli bound to protein matrix
Bacterial cast
Describe the appearance of epithelial cells in urine
RTE cells attached to protein matrix
Describe the appearance of Granular casts in urine
Coarse and fine granules in a cast matrix
Cite the clinical significance of finding an abnormal value of bacterial casts in urine
Pyelonephritis
What is the clinical significance of finding abnormal values of epithelial casts in urine?
Renal tubular damage
What are the clinical significance of finding abnormal values of fatty casts in urine?
- Nephrotic syndrome
- Toxic tubular necrosis
- Diabetes mellitus
- Crush injuries
What is the clinical significance of finding abnormal values of broad casts in urine?
- Extreme urine stasis (remember this basin mogawas chariz)
- Renal failure
What is the clinical significance of finding abnormal values of waxy casts in urine?
- Stasis of urine flow (same2 sa broad casts pero extreme lang sa broad :P)
- Chronic renal failure
The matrix of this cast appears wider than normal
Broad cast
Fat droplets and oval fat bodies are attached to the protein matrix of this cast
Fatty cast
These cells are seen in cases of hepatitis
Bilirubin- stained RTE cells
This cast is highly refractile under bright-field microscopy
Fatty casts
Reporting of crystals in urine:
Rare, few, moderate, or many per HPF
Reporting of abnormal crystals in urine:
Average per LPF
This is a valuable aid in the identification of crystals
pH of the specimens
This crystal precipitates in both acidic and neutral urine
Calcium oxalate
ALL abnormal crystals are found in what type of urine?
Acidic urine (rarely in neutal urine)
The most common crystals found in acidic urine is?
Urates (consisting of amorphous urates, uric acid, acid urates, and sodium urates)
This crystal is fequently encountered in
specimens that have been refrigerated and produce a very characteristic pink sediment
Amorphous urates
This crystal is found in acidic urine with a pH greater than 5.5
Amorphous urates
This crystal is seen in a variety of shapes, including rhombic, four-sided flat plates (whetstones), wedges, and rosettes
Uric acid
This crystal is highly birefringent under polarized light
Uric acid
These crystals are frequently seen in acidic urine, but they can be found in neutral urine and even rarely in alkaline urine.
Calcium oxalate
Most common form of calcium oxalate. Appears as colorless octahedral envelope or as two pyramids joined at their bases
Dihydrate
What are the clinical significance of finding clumps of calcium oxalate crystals in fresh urine? Pathologic and non-pathologic
Pathologic: Formation of renal calculi
Non-pathologic: Ingestion of foods high in oxalic acid such as tomatoes and asparagus, and ascorbic acid
The primary
pathologic significance of calcium oxalate crystals is the:
very noticeable presence of monohydrate form in cases of ethylene glycol (antifreeze) poisoning
These crystals are easily identified by their prism shape that frequently resembles a “coffin lid”
Triple phosphate (ammonium magnesium phosphate)
These crystals have no clinical significance; however, they are often seen in highly alkaline urine associated with the presence of urea-splitting bacteria
Triple phosphate crystals
They appear as colorless, flat rectangular plates or
thin prisms often in rosette formations
Calcium phosphate
These crystals have no clinical significance, although is a common constituent of renal calculi
Calcium phosphate
These crystals appears small and colorless, with dumbbell or spherical shape
Calcium carbonate crystals
These crystals exhibit the characteristic yellow-brown color of the urate crystals seen in acidic urine. They are frequently described as “thorny apples”
Ammonium biurate
These crystals resemble other urates in that they dissolve at 60°C and convert to uric crystals when glacial acetic acid is added
Ammonium biurate
These crystals are almost always encountered in
old specimens and may be associated with the presence of the ammonia produced by urea-splitting bacteria
Ammonium biurate
This crystal appears as colorless, hexagonal plates and
may be thick or thin
Cystine crystals
These crystals are found in the urine of persons who inherit
a metabolic disorder that prevents reabsorption of cystine by the renal tubules (cystinuria)
Cystine crystals
Positive confirmation of cystine crystals is made using what type of test?
Cyanide-nitroprusside test
These crystals are rarely seen unless specimens have
been refrigerated, because the lipids remain in droplet form.
Cholesterol crystals
These crystals have a most characteristic appearance,
resembling a rectangular plate with a notch in one or more corners
Cholesterol crystals
They are associated with disorders producing lipiduria, such as the nephrotic syndrome, and are seen in conjunction with fatty casts and oval fat bodies
Cholesterol crystals
This crystal appears as colorless flat plates and is associated iwth radiographic procedure
Radiographic dye crystals
These abnormal crystals are associated with liver disorders
Tyrosine, leucine, and bilirubin
These crystals appear as fine colorless to yellow needles
that frequently form clumps or rosette
Tyrosine crystals
These crystals are may also be encountered in inherited disorders of amino acid metabolism
Tyrosine crystals
These crystals appear as yellow-brown spheres that demonstrate
concentric circles and radial striations
Leucine
These crystals are present in hepatic disorders producing
large amounts of bilirubin
Blirubin crystals
These crystals appear as
clumped needles or granules with the characteristic yellow
color
Blirubin crystals
Finding of these crystals in the urine of patients being treated
for UTIs was common
Sulfonamides crystals
What is the primary cause of sulfonamide crystallization?
Inadequate patient hydration (inom lage’g tubig. This is your sign to drink water >:P )
These crystals appear as colorless needles that tend to form bundles following refrigeration
Ampicillin crystals
Disorder associated with tyrosine, leucine, and bilirubin crystals:
Liver disease
These are abnormal crystals that can be found in both acid and neutal pH
- Leucine
- Tyrosine
- Sulfonamides
- Ampicillin
Disorder associated with cholesterol crystals:
Nephrotic syndrome
Disorder associated with both sulfonamides and ampicillin crystals:
infection treatment
Disorder associated with Radiographic dye:
Radiographic procedure
What are the most frequently encountered artifacts in urine?
starch, oil droplets, air bubbles, pollen grains, fibers, and fecal
contamination
Note:
Reporting of artifacts is NOT necessary
These artifacts are highly refractile and may resemble RBCs to inexperienced laboratory personnel.
Oil droplets and air bubbles
These are seasonal contaminants that appear as spheres with a cell wall and occasional concentric circles
Pollen grains
These are artifacts thay may initially be mistaken for cast
Hair and fibers
These artifacts may appear as
plant and meat fibers or as brown amorphous material in a
variety of sizes and shapes
Fecal artifacts
These crystals are easily identified by their prism shape that frequently resembles a “coffin lid”
Triple phosphate (ammonium magnesium phosphate)