CHAPTER 7: MICROSCOPIC EXAM Flashcards
May cause precipitation of amorphous urates and phosphates and other nonpathologic crystals that can obscure other elements in the urine sediment
Refrigeration
Standard amount of urine
10 - 15 mL (12mL: frequently used)
Recommended volume when using the conventional glass-slide method
20 uL (0.02 mL)
*covered by a 22 x 22 mm glass cover slip
How many fields should be observed and in what power?
Min. of 10 fields, under both low (10x) and high (40x) power
The slide is examined in this power to detect casts and ascertain the general composition of the sediment.
low power
*locate near the edges of the cover slip
Note:
R e p o r t i n g
1) casts: ave #/10 lpf
2) RBCs & WBCs: ave#/10 hpf
3) epithelial & crystals: rare, few, mod, many (1+, 2+, ….)
Developed the first procedure to standardize the quantitation of formed elements in the urine microscopic analysis in 1926
Addis
Most frequently used stain in urinalysis which consists of crystal violet and safranin O
Sternheimer-Malbin stain
Used for the visualization of elements with low refractive indices (hyaline casts, cellular casts, mucous threads, Trichomonas)
Phase-contrast microscopy
Used for the identification of cholesterol in Oval Fat Bodies and crystals
Polarizing microscopy
This stain delineates the structure and contrasting colors of the nucleus and cytoplasm.
ID: WBCs, epithelial cells, and casts
Sternheimer-Malbin
This stain enhances nuclear detail.
Differentiates WBCs and RTE
Toluidine blue
This stain lyses RBCs and enhances nuclei of WBCs.
Distinguishes RBCs from WBCs, yeast, oil droplets, and crystals
2% acetic acid
Stains triglycerides and neutral fats orang-red. It does not stain cholesterol.
Oil Red O and Sudan III (Lipid stains)
A stain that identifies bacterial casts either positive or negative.
Gram stain
This stain identifies urinary eosinophils
Hansel stain
Stains structures containing iron.
Identifies yellow-brown granules of hemosiderin in cells and casts
Prussian blue stain
NV:
1) RBCs
2) WBCs
1) 0-2 or 0-3/hpf
2) 0-5 or 0-8/hpf
In _______________ urine, the cells shrink due to loss of water and may appear crenated or irregularly shaped.
hypersthenuric/ hypertonic/concentrated
In _____________ urine, the cells absorb water, swell, and lyse rapidly, releasing their hemoglobin and leaving only the cell membrane.
dilute/hypotonic/hypothenuria
Large empty cells
ghost cells
RBCs that vary in size, have cellular protrusions, or are fragmented and have been associated primarily with glomerular bleeding
Dysmorphic
The dysmorphic cell most closely associated with glomerular bleeding
Acanthocyte with multiple protrusions
Predominant WBC found in the urine sediment.
Neutrophils
Brownian movement of the granules within these large wbcs produces a sparkling appearance, and they are referred to as _____________.
Glitter cells
Its presence in the urine is associated with drug-induced interstitial nephritis, UTI, and renal transplant rejection.
Eosinophils
Significant percentage of eosinophils in urine
> 1%
Quantitative measure of formed elements or urine using hemacytometer
Addis count
Specimen for Addis Count and preservative used.
12 hr urine; formalin
Increase in urinary WBCs that indicates infection or inflammation in the genitourinary system.
Pyuria
The largest cells found in the urine sediment
squamous epithelial cells
A variation of the squamous epithelial cell
which does have pathologic significance and are indicative of vaginal infection by the bacterium Gardnerella vaginalis.
Clue cells
Cells that are smaller than squamous cells and appear in several forms, including spherical, polyhedral, and caudate
Transitional (Urothelial) Cells
Increased numbers of these cells are seen singly, in pairs or in clumps (syncytia) which are present following invasive urologic
procedures such as catheterization and are of no clinical significance.
Transitional (Urothelial) Cells
For RTE cells,
1) rectangular, columnar/convoluted
2) round/oval
a. PCT
b. DCT
1) rectangular, columnar/convoluted
- PCT
2) round/oval
- DCT
Cells often present as a result of tissue destruction (necrosis)
RTE cells
Number of RTE cells per hpf that indicates tubular injury
> 2
Contain the characteristic yellow-brown hemosiderin granules
RTE cells
Lipid containing RTE cells
Oval Fat Body
Examination of oval fat bodies using polarized light results in the appearance of characteristic _____________ formations in droplets containing
cholesterol.
maltese cross
RTE cells containing large, nonlipid-filled vacuoles seen along with normal renal tubular cells and oval fat bodies in Acute Tubular Necrosis.
Bubble cells
The bacteria most frequently associated with UTI
Enterobacteriaceae ( gram-negative rods)
- also Staphylococcus and Enterococcus (cocci-shaped)
Yeast cells seen in the urine of diabetic patients, immunocompromised patients, and women with vaginal moniliasis
Candida albicans
Its presence counts for a true yeast infection
WBCs
A trophozoite, pear-shaped flagellate with an undulating membrane, identified by its rapid darting movement
Trichomonas vaginalis
Causes pingpong disease
T. vaginalis
A bladder parasite whose ova can be seen in urine
S. haematobium
Most common fecal contaminant
E. vermicularis
Major constituent of mucus
Uromodulin
A protein material produced by the glands and epithelial cells of the lower genitourinary tract and the RTE cells that appear microscopically as threadlike structures.
Mucus
Only elements found in the urinary sediment that are unique to the kidney
Casts
Where the casts are formed providing the microscopic view of conditions within the nephron
DCT and CD
Major constituent of casts
Tamm-Horsfall Protein (Uromodulin)
Formation of casts at the junction of the ascending loop of Henle and the DCT may produce structures with a tapered end.
Cylindroids
Refers to the presence of urinary casts
Cylinduria
Stain produces a pink color in hyaline casts
Sternheimer-Malbin
Most frequently seen cast
Hyaline
This cast indicates bleeding within the nephron
RBC cast
These casts in the urine signifies infection or inflammation within the nephron and are most frequently associated with pyelonephritis and are a primary marker for distinguishing pyelonephritis (upper UTI) from cystitis (lower UTI).
WBC casts
Confirmation of bacterial casts is best made by performing a ______________ on the dried or cytocentrifuged sediment.
Gram stain
Origin of the granular cast in nonpathological conditions
Lysosomes
Formed from the disintegration of cellular casts
Fine/Course Granular Cast
Seen in conjunction with oval fat bodies and free fat droplets in disorders causing lipiduria. These are associated most frequently with nephrotic syndrome.
Fatty casts
These casts are representative of extreme urine stasis, indicating chronic renal failure. It is believed to be caused by degeneration of the hyaline cast matrix and any cellular elements or granules contained in the matrix (all)
Waxy casts
Often appear fragmented with jagged ends and have notches in their sides
Waxy casts
Often referred to as renal failure casts
Broad casts
These casts indicates destruction (widening) of the tubular walls.
Broad casts
Bile stained casts that are seen as the result of tubular necrosis caused by viral hepatitis
Broad, waxy
Formed by the precipitation of urine solutes, including inorganic salts, organic compounds, and medications (iatrogenic compounds)
Crystals
1) organic and iatrogenic compounds
2) inorganic salts
a. Acidic pH
b. Alkaline pH
1) organic/iatrogenic - acidic
2) inorganic - alkaline
A crystal that precipitates in both acidic and neutral urine
Calcium oxalate
The most valuable initial aid for identifying crystals in a urine specimen
pH
Normal acidic crystals in urine
Uric Acid
Amorphous Urates
Sodium Urate
Normal alkaline crystals
Calcium phosphate
Amorphous phosphate
Triple phosphate
Ammonium biurate
Calcium carbonate
Crystals encountered frequently in specimens that have been refrigerated but disappear when the urine is warmed. They produce a very characteristic pink sediment caused by accumulation of the pigment uroerythrin on the surface of the granules
Amorphous urates
Crystal with variety of shapes: Rhombic, wedge, rosette, hexagonal, four-sided plate (whetstone)
Uric acid
Increased amounts of these crystals are seen in patients with leukemia who are receiving chemotherapy, in patients with Lesch-Nyhan syndrome, and sometimes in patients with gout.
Uric acid
Crystals that are needle shaped and are seen in synovial fluid during episodes of gout, but they also may appear in the urine
Sodium urate
The most common form of calcium oxalate crystals
Dihydrate (weddelite)
Majority of the composition of renal calculi
Calcium oxalate
Coffin lid, “Struvite”, staghorn appearance that indicates the presence of urea-splitting bacteria
Triple phosphate
Colorless, flat rectangular plates or thin prisms often in rosette formation
Calcium phosphate
Frequently they are described as “thorny apples” because of their appearance as spicule-covered spheres and are almost always associated with old specimen
Ammonium biurate
Crystals that appear as colorless, hexagonal plates and may be thick or thin
Cysteine
They have a most characteristic appearance, resembling a rectangular plate with a notch in one or more corners
Cholesterol
Crystals usually seen in liver disease
Tyrosine, leucine, bilirubin
Colorless to yellow needles crystals more common in liver disease
Tyrosine
Yellow-brown spheres w/ concentric circles and radial striations
Leucine
Crystals appearing as clumped needles or granules w/ yellow color
Bilirubin
Primary cause of sulfonamide crystallization
Inadequate hydration
Rare observation of these crystals after massive doses of this penicillin compound without adequate hydration
Ampicillin
