Microscopic exam of urine pt 1 Flashcards
RBCs normal value in urine
0-2 per hpf
How do RBCs look in concentrated urine?
Small and crenated bc hypertonic
How do RBCs look in dilute urine
- Ghost cells = Swollen, lysed, membrane intact
- Don’t count, just note
RBCs confused with
- Yeast
- Oil droplets
- Air bubbles
Hematuria
RBC in urine
Explain how presence or absence of RBCs may not correlate with urine color or blood chemical result
- 1-4 RBC/hpf but chem strip negative
- Chem strip positive but no RBC seen microscopically due to RBC lysis, hemoglobin, or myoglobin
Acetic acid lyses ___ but not ____
- RBCs
- Yeast, WBCs, or oil droplets
Dysmorphic RBCs (cellular protrusions, vary in size, fragmented) big sign of ___
- Glomerular bleeding
- Rarely seen due to strenuous exercise
- 2nd tech review required bc rare and looks like yeast
WBC normal value
0-5 per hpf
WBC size and usual identity
- 12 microns
- PMN
WBCS in hypertonic urine
How they look
Leukocyte esterase reaction
- Shrink
- Do not release granules, may be negative for leukocyte esterase strip test
WBC hyptonic urine
Swell
Glitter cells
- WBCs in hypotonic urine swell, thus granules undergo Brownian movement to cause glittering
- Not pathologically significant
Pyuria
Increased WBCs in urine
Causes of pyuria
- Bacterial infection
- Glomerulonephritis
- Lupus erythematosus
- Interstitial nephritis
- Tumors
- Parasites
- Fungi
Mononuclear cells in urine
- Less common to see
- Lymphs (may resemble RBC), monocytes, macrophages, histocytes
Lymphs seen in urine when
Early stages of renal transplant rejection
What to do with urine that has a lot of mononuclear cells?
Refer to cytology
Eosinophils associated with
- Drug-induced interstitial nephritis (primary reason)
- UTI
- Parasites
- Renal transplant rejection
How to stain for eosinophils in UA
Hansel’s or Wright’s stain
Clinically significant eosinophil value
Eos > 1%
List 3 types of epithelial cells and their sources
- Squamous (urethra/genitalia)
- Transitional (upper urethra)
- Renal tubule (PCT, DCT, Henle, collecting duct aka nephron)
ID this cell
RTE
ID these cells
Squamous
ID this cell
Transitional cell
What cell am I describing
Largest cells in urinary sediment, nucleus about RBC size, easily seen under 10x, slough off, may look like casts, degenerate easily
Squamous cells
Clue cells
- Squamous cells with 75% bacteria
- Indicate bacterial vaginosis (Gardnerella vaginalis)
Are clue cells reported in hospitals?
Not usually, they are reported as normal squamous epithelial cells instead
What cell am I describing
Central nuclei, numerous forms, well defined edge
Transitional epithelial cell!
Transitional epithelial cell normal value
0-2 hpf
Increased amounts of transitional epithelial cells due to
Catheterization, but not pathologic in this case
Transitional epithelial cells with vacuoles or irregular nuclei may indicate
Viral infection, refer to cytology
What cell am I describing
Cuboidal, columnar, or round, flattened edge, eccentric nuclei
RTE cells
RTE normal value and clinically significant value
- 0-2/hpf normal
- RTE > 3/hpf indicates damage or necrosis to renal tubules (infection, drug toxicity, heavy metals, allergic reactions)
Since RTE cells reabsorb glomerular filtrate, what elements can they contain?
- Bilirubin = yellow color
- Hemosiderin = yellow-brown granules
Oval fat bodies
- RTE cells that absorbed lipids from glomerular filtrate
- Highly pathogenic and rare
When are oval fat bodies typically seen
Seen along with free fat droplets and or fatty casts
Lipiduria
Fat in urine
Lipiduria associated with
- Nephrotic syndrome (glomerular damage)
- Tubular necrosis
- Diabetes mellitus
- Trauma (BM fat)
- Oval fat bodies from histocytes instead of RTE, which are seen in lipid storage diseases
How do you detect oval fat bodies under the microscope?
- Stain with Oil Red O or Sudan III
- Polarizing microscopy to see if there’s cholesterol
Oval fat bodies easily confused with
Starch or certain crystals
ID the following
Oval fat body
What does cholesterol look like under polarizing microscopy?
Maltese cross
If bacteria present, what reagent test strip results do you expect?
- Nitrite positive or negative
- Positive leukocyte esterase if WBC present
Collection method for urine samples suspected to contain bacteria
Clean catch or random specimen
Increased amounts of bacteria in urine suggest ___. What’s the follow-up test?
- UTI
- Do quantitative urine culture
ID the element
Usually Candida albicans
Yeast appears in
- Diabetes mellitus (acid pH and more glucose)
- Immunocompromised pts
- Vaginal yeast infections
If yeast are present, what other element should be present?
WBCs
Major constituent of mucus
Tamm-Horsfall protein (uromodulin)
Mucus refractive index
- Low, making it hard to see
- More frequent in female urines
Mucus clinical significance
None for males or females
ID the element
Mucus
Increased amounts of semen may produce what positive result on chemical strip test?
Positive protein
ID the element
Sperm
What clinically insignificant causes of bacteria in urine are there?
- Normal sloughing off normal flora from genitalia
- Urine sat out more than 2 hrs