Casts, Crystals, and other elements

Hyaline cast

Increased with exercise, dehydration, heat, and emotional stress.

May be seen in acute glomerularnephritis, pyelonephritis, chronic renal disease, and congestive heart failure.

RBC cast

RBCs are embedded in the matrix and must be clearly identifiable. Presence indicates acute glomerulonephritis, glomerular disease or glomerular damage.

Also seen in strenuous sports.

Hemoglobin cast

This cast is associated glomerular disease glomerular damage, and acute glomerulonephritis.

Appears reddish brown due to hematin formation. Accompanied by hematuria. Associated

WBC cast

Cast with leukocytes embedded in the matrix.

Associated with inflammation, infection, and renal tubular disease.

Renal tubular epithelial cast

Form as a result of stasis and necrosis of the tubules.

Presence can be seen in severe chronic kidney disease, exposure to nephrotic agents or viruses, rejection to kidney transplants.

Granular Casts

Thought to be from breakdown of cellular cast components.

Progressive cellular deterioration leads to appearance of coarse granules which transition into fine granules.

Presence is associated with renal disease.

Waxy cast

Appear as smooth homogenous cylinders with blunt broken ends and cracked and serrated edges that are highly refractile.

Associated with severe chronic renal failure, malignant hypertensions, diabetic nephropathy, acute renal disease, and renal transplant rejection.

Fatty cast

Cast with incorporated fat droplets. If cholesterol is present it makes a Maltese cross under light.

Seen with diabetes, and nephrotic syndrome.

Uric acid crystal

Forms in acidic pH

Seen in patients with gout, chemotherapy, and Lesch-Nyhan syndrome.

Calcium oxalate crystal

Forms in acidic, alkaline, and neutral urine

Dihydrate form: Predominate in urine from patients with diets rich in oxalic acid, most common cause of kidney stones

Monohydrate form: Predominate urine from patients who have ingested ethylene glycol.

Hippuric Acid

Form in acidic or neutral pH

Little to no clinical significance, seen in people who work with organic substances.

Calcium phosphate crystals

Form in neutral and alkaline pH

Seen in metabolic disorders and medications that alter pH

Triple phosphate crystals

Form in alkaline urine

Presence is insignificant

Seen in dog urine specimens with UTIs

Calcium carbonate crystals

Form in alkaline pH

Not clinically significant

Ammonium biurate crystals

Form in alkaline pH

Presence may be significant if formed in-vivo (dehydration)

Amorphus urates

Form in acidic pH

Seen in refrigerated samples, soluble at alkaline pH or if heated over 60 Celsius

Amorphus phosphates

Form in alkaline pH

Seen in refrigerated samples as white sediment

Soluble in acetic acid and does not dissolve if heated over 60 Celsius

Cystine crystals

Form in acidic pH

Associated with inborn errors of metabolism such as hereditary cystinosis or cystinuria. Most common cause on kidney stones in children.

Leucine crystals

Form in acid pH

Presence associated with inborn errors of metabolism

Tyrosine crystals

Form in acidic pH

Associated with inborn errors of metabolism such as tyrosinemia and certain liver disorders.

Ampicillin crystals

Form in acidic pH

Sulfonamide crystals

Form in acidic pH

Indinavir crystals

Radiopaque dye crystals

Associated with high SG results by refractometer

Bilirubin crystals

Form in acidic pH

Form from conjugated _________

Associated with hepatic disorders and liver disease