microscopic examination of urine

Bright-field Microscopy

Used for routine urinalysis

Dark-field Microscopy

Identification motility of spirochetes (Treponema pallidum)

Fluorescence Microscopy

Visualization of naturally fluorescent microorganisms

Polarizing Microscopy

Used in identification of crystals , cholesterol in oval fat, and fatty casts

Interference-Contrast Microscopy

Three dimensional microscopy image

Phase-Contrast Microscopy

Visualization of elements with low refractive indices

CREBPAYS

• Casts

• Red blood cells

• Epithelial cells

• Bacteria

• Pus cells

• Animal parasites

• Yeast cells

• Spermatozoa

Organized/Formed elements

range/LPF

REPORTING

Casts

range/HPF

REPORTING

RTE, RBC, and pus cells

Sternheimer-Malbin

STAINS AND SOLUTIONS

• Differentiates pus cells (pink) from glitter cells (pale blue)

• Stains epithelial cells and casts

0.5% Toluidine Blue

STAINS AND SOLUTIONS

• Differentiates WBC from RTE

2% acetic acid

STAINS AND SOLUTIONS

• Differentiates RBC from WBC, yeast

Hansel Stain

STAINS AND SOLUTIONS

• Stain for urinary eosinophils

Prussian Blue

STAINS AND SOLUTIONS

• Stain iron-containing structures

Cast

• Composed of Tamm-Horsfall protein (aka uromodulin) excreted by renal tubular epithelial cells

• cylindrical

• formed in the Ascending loop of henle towards distal convoluted tubule and in the connecting duct

Hyaline Cast

CASTS

• protein matrix alone without enmeshed structure

• “prototype” cast

RBC Cast

CASTS

• patients suffering from glomerular bleeding

Pus/WBC Cast

CASTS

• patients suffering from pyelonephritis

Bacterial Cast

CASTS

• In case of sepsis (bacteremia)

Epithelial Cell Casts

CASTS

• In case of renal transplant rejection

Broad Cast

CASTS

• bad prognosis due to inflammation of tubules

• End stage renal disease

Waxy Cast

CASTS

• final degenerative form of casts

Red Blood Cells

• Small, non-nucleated discs

• Appear crenated in concentrated urine

Ghost cells

RED BLOOD CELLS

• larger empty cells in dilute/hypotonic urine

Dysmorphic RBCs

RED BLOOD CELLS

• indicates glomerular bleeding

Hemoglobinuria or Myoglobinuria

RED BLOOD CELLS

• A clear red urine with a positive reagent strip RBC and no RBCs in the microscopic analysis

Neutrophils

WHITE BLOOD CELLS

• multilobed nuclei and granules

Eosinophils

WHITE BLOOD CELLS

• red granules when stained with Wright or Hansel stains

Glitter cells

WHITE BLOOD CELLS

• neutrophils that have swollen in dilute urine, resulting in Brownian movement of the granules

• degenerative form

Squamous Cells

EPITHELIAL CELLS

• Frame of reference

• Largest cells in the urine sediment

• Represent normal sloughing of old lower genitourinary tract cells

Clue Cells

EPITHELIAL CELLS - Squamous Cells

• squamous epithelial cells covered with Gardnerella vaginalis bacteria, indicating a vaginal infection

Transitional (Urothelial) Cells

EPITHELIAL CELLS

• Found in the renal pelvis, ureters, bladder, and male urethra

• bladder cells

• donut-like around

• Spherical cells resemble renal tubular cells, except they have centrally located nucleus

Renal Tubular Epithelial Cells

EPITHELIAL CELLS

• found in the renal tubes and collecting duct

• Tubular necrosis, often from poisoning or viral infections

Convoluted tubule cells

EPITHELIAL CELLS - RTEs

• rectangular with coarse granules and may be resemble a cast

Distal convoluted tubule cells

EPITHELIAL CELLS - RTEs

• small and round, may resemble spherical transitional cells but have an eccentric nucleus

Oval Fat Bodies

EPITHELIAL CELLS - RTEs

• absorbed lipids

• Highly refractile

• Confirm by staining with Oil red O, Sudan II or polarized microscopy

  • appear maltese cross appearance

• Clinical significance: Nephrotic syndrome, diabetes mellitus, and crush injuries

Bubble cells

EPITHELIAL CELLS - RTEs

• renal tubular epithelial cells that absorbed non-lipid substance

Bacteria

• Small spheres (cocci) and rod-shaped organisms

• should be accompanied by WBCs

• Urinary tract infection

Yeast

• Oval structures with buds or mycelia

• Associated with acidic urine from patients with diabetes mellitus

Trichomonas vaginalis

exhibits rapid flagellar movement in wet preparation

Mucus Threads

Strands of protein secreted by glands and renal tubular epithelial cells

Uric Acid

NORMAL CRYSTALS (ACIDIC)

• flat-sided rhombic plates, wedges, and rosettes

• Yellow-brown

• Pleomorphic

• Lesch-Nyhan disease

Amorphous Urates

NORMAL CRYSTALS (ACIDIC)

• Small spheres producing brick-dust or yellow-brown sediment

Dihydrate form

NORMAL CRYSTALS (ACIDIC) - Calcium Oxalate

• envelope shaped

• clumps in fresh urine may indicate renal calculi

Monohydrate form

NORMAL CRYSTALS (ACIDIC) - Calcium Oxalate

• oval or dumbbell shaped

• presence of this form indicates ethylene glycol ingestion

Triple Phosphate

NORMAL CRYSTALS (ALKALINE)

• aka struvite

  • magnesium - ammonium - sulfate

• coffin lid shaped

• very high pH and bacteria found in old specimens

Amorphous Phosphates

NORMAL CRYSTALS (ALKALINE)

• white precipitate after refrigeration

Calcium Carbonate

NORMAL CRYSTALS (ALKALINE)

• Dumbbell and spherical shapes

• Produce gas with acetic acid

Ammonium Biurate

NORMAL CRYSTALS (ALKALINE)

• Yellow-brown thorny apple-shaped crystals

Cystine

ABNORMAL CRYSTALS

• Hexagonal flat plates

• An inherited disorder that inhibits the reabsorption of cystine by the renal tubules

• not liver related

Tyrosine

ABNORMAL CRYSTALS

• Yellow needle-shaped forms in clusters or rosettes

Cholesterol

ABNORMAL CRYSTALS

• Rectangular plates with notched corners

• highly birefringent under polarized light

• UNSTAINED with lipid stains

Leucine

ABNORMAL CRYSTALS

• Yellow-brown spheres with concentric circles

Bilirubin

ABNORMAL CRYSTALS

• Bright yellow clumped needles and granules

• Broom stick-like crystals

Sulfonamides

ABNORMAL CRYSTALS - Drug-induced

• Needle, rosette and rhombic shapes

Ampicillin

ABNORMAL CRYSTALS - Drug-induced

• Colorless needles that form clumps after refrigeration

Starch

ARTIFACTS

• Refractile spheres with concentric circles

• contamination from powdered gloves

Air bubbles/Oil droplets

ARTIFACTS

Refractile spheres

Pollen grain

ARTIFACTS

spheres with concentric circles

Fibers

ARTIFACTS

elongated strips

B. Crystals

RECALL QUESTIONS

Organized type of urine sediments, except:

A. Casts

B. Crystals

C. Epithelial Cells

D. Bacteria/Parasites

C. Enterobius vermicularis

RECALL QUESTIONS

Parasites possibly noted in urine sediments in microscopy, except:

A. Schistosoma japonicum

B. Trichomonas vaginalis

C. Enterobius vermicularis

D. Schistosoma haematobium

C. Cystine

RECALL QUESTIONS

Abnormal urinary crystals noted in liver disorders, except:

A. Tyrosine

B. Leucine

C. Cystine

D. Bilirubin

B. RBC

RECALL QUESTIONS

Casts: its presence is ALWAYS pathologic; strongly indicative of glomerular damage:

A. WBC

B. RBC

C. Hyaline

D. Granular