CH1350 3.5 Intro to Microscopic Examination of Urine

Flashcards for reviewing key concepts in urine microscopy.

Kova System

A standardized system used in urine microscopy to ensure consistent preparation and analysis of urine sediment.

Sedi-stain

Common stain used to enhance the visibility of cellular elements in urine sediment under microscopic examination.

Bright-Field Microscopy

Microscopy technique used for routine urine analysis where objects appears dark against a light background.

Phase Contrast Microscopy

Microscopy technique that enhances the visibility of elements with low refractive indices such as hyaline casts and mucous threads.

Polarizing Microscopy

Microscopy technique used to identify cholesterol (Maltese cross) and improve identification of lipids and crystals in urine. Also brings out cast details.

Hypersthenuric Urine

Concentrated urine where RBCs shrink and appear crenated (SG > 1.010).

Hyposthenuric Urine

Dilute urine where RBCs swell and lyse rapidly, forming ghost cells (SG < 1.010).

Dysmorphic RBCs

RBCs that vary in size and have cellular protrusions or are fragmented, seen with glomerular bleeding. May also be seen with strenuous exercise or nonglomerular hematuria.

Glitter Cells

Neutrophils in urine that exhibit Brownian movement of granules, producing a sparkling appearance in hypotonic urine; not pathologically significant.

Pyuria

An increase in urinary leukocytes, typically indicating a bacterial infection or non-bacterial inflammation.

Squamous Epithelial Cells

Largest cell found in urine sediment, originating from the linings of the urethra and vagina; a large number may indicate non-midstream collection, particularly in female specimens. Fried egg appearance.

Clue Cells

Squamous epithelial cells covered with Gardnerella vaginalis coccobacillus, indicating bacterial vaginosis.

Transitional Epithelial Cells

Epithelial cells that line the renal pelvis, calyces, ureters, bladder, and upper male urethra; increased numbers may indicate inflammation or infection. Poached egg appearance.

Renal Tubular Epithelial Cells (RTEs)

Most clinically significant epithelial cells in urine; increased numbers (> 2 RTE cells/hpf) indicate tubular injury or renal tubular necrosis. May have a boiled egg appearance.

Oval Fat Bodies

RTE cells containing lipids; found in patients with nephrotic syndrome and confirmed by staining with Sudan III or Oil Red O. Under polarized light, oval fat bodies will demonstrate a Maltese cross.

Enterobacteriaceae

Gram-negative rods that are the bacteria most associated with UTIs.

Trichomonas vaginalis

Most frequently seen parasite in urine; a pear-shaped, sexually transmitted pathogen with an undulating membrane and rapid darting movement when motile.

Uromodulin

Glycoprotein excreted by RTE cells of the distal convoluted tubules and upper collecting ducts; major constituent of mucus in urine. May be confused with hyaline casts.

Starch Granules

Highly refractive spheres with dimpled center, representing contamination from powdered gloves; show a Maltese cross formation when polarized.

Acetic Acid

Can be added to differentiate RBCs (will lyse) from yeast, WBCs, and air bubbles

Pyelonephritis

Inflammation of the kidney

Cystitis

Inflammation of the bladder