Urinalysis-Urine Microscopy and Clinical Correlations

Which of the following dyes are used in Sternheimer-Malbin stain?

Crystal violet and safranin

Which of the following statements regarding WBCs in urinary sediment is true?

WBC casts indicate that pyuria is of renal, rather than lower urinary, origin

Which description of sediment with Sternheimer-Malbin stain is correct?

Transitional epithelium: cytoplasm pale blue, nucleus dark blue

SITUATION: A 5mL urine specimen is submitted for routine urinalysis and analyzed immediately. The SG of the sample is 1.012 and the pH is 6.5. The dry reagent strip test for blood is a large positive (3+) and the microscopic examination shows 11-20 RBCs per HPF. The leukocyte esterase reaction is a small positive (1+), and the microscopic examination shows 0-5 WBCs per HPF. What is the most likely cause of these results?

Insufficient volume is causing microscopic results to be underestimated

Which of the following statements regarding epithelial cells in the urinary system is correct?

Transitional cells originate from the upper urethra, ureters, bladder, or renal pelvis

Which of the statements regarding examination of unstained sediment is true?

Large numbers of transitional cells are often seen after catheterization

Which of the following statements regarding cells found in urinary sediment is true?

Renal tubular cells are often polyhedral and have an eccentric round nucleus

Which of the following statements regarding RBCs in the urinary sediment is true?

RBCs of glomerular origin often appear dysmorphic

Renal tubular epithelial cells are shed into the urine in largest numbers in which condition?

Cytomegalovirus (CMV) infection of the kidney

The ova of which parasite may be found in the urinary sediment?

Trichuris trichiura

Oval fat bodies are often seen in:

Nephrotic syndrome

All of the following statements regarding urinary casts are true except:

Casts can be seen in significant numbers even when protein tests are negative

Which condition promotes the formation of cases in the urine?

Reduced filtrate formation

The mucoprotein that forms the matrix of a hyaline cast is called:

Tamm-Horsfall protein

"Pseudocasts" are often caused by:

Amorphus urates

Which of the following statements regarding urinary casts is correct?

Broad casts are associated with severe renal tubular obstruction

A sediment with moderate hematuria and RBC casts most likely results from:

Acute glomerulonephritis

Urine sediment characterized by pyuria with bacterial and WBC casts indicates:

Pyelonephritis

Which type of casts signals the presence of chronic renal failure?

Waxy casts

SITUATION: Urinalysis of a sample from a patient suspected of having a transfusion reaction reveals small yellow-brown crystals in the microscopic examination. Dry reagent strip tests are normal with the exception of a positive blood reaction (moderate) and trace positive protein. The pH of the urine is 6.5 What test should be performed to positively identify the crystals?

Prussian blue stain

When examining urinary sediment, which of the following is considered an abnormal finding?

0-1 renal cell casts per LPF

SITUATION: A urine sample with a pH of 6.0 produces an abundance of pink sediment after centrifugation that appears as densely packed yellow- to reddish-brown granules under the microscope. The crystals are so dense that no other formed elements can be evaluated. What is the best course of action?

Suspend the sediment in prewarmed saline, then repeat centrifugation

How can hexagonal uric acid crystals be distinguished from cystine crystals?

Cystine gives a positive nitroprusside test after reduction with sodium cyanide

The presence of tyrosine and leucine crystals together in a urine sediment usually indicates:

Chronic liver disease

Which of the following crystals is considered nonpathological?

Ammonium biurate

At which pH are ammonium biurate crystals usually found in urine?

Alkaline urine only

Which of the following crystals is seen commonly in alkaline and neutral urine?

Magnesium ammonium phosphate

Which crystal appears in urine as a long, thin hexagonal plate, and is linked to ingestion of large amounts of benzoic acid?

Hippuric acid

Small yellow needles are seen in the sediment of a urine sample with a pH of 6.0. Which of the follwoing crystals can be ruled out?

Cholesterol crystals

Oval fat bodies are derived form:

Renal tubular epithelium

Oval fat bodies are often associated with:

Lipoid nephrosis

Urine of constant SG ranging from 1.008 to 1.010 most likely indicates:

Renal tubular failure

Which of the following characterizes prerenal failure, and helps to differentiate it from acute renal failure caused by renal disease?

BUN: creatinine ratio of 20:1 or higher

Which of the following conditions characterizes chronic glomerulonephritis and helps to differentiate ti from acute glomerulonephritis?

Polyuria

Which of the following conditions is seen in acute renal failure and helps to differentiate it from prerenal failure?

Abnormal urinary sediment

Which of the following conditions characterizes acute renal failure and helps to differentiate it form chronic renal failure?

Hyperkalemia

The serum concentration of which analyte is likely to be decreased in untreated cases of acute renal failure?

Calcium

Which of the following conditions is associated with the greatest proteinuria?

Nephrotic syndrome

Which of the following conditions is often a cause of glomerulonephritis?

Systemic lupus erythematosus

Acute pyelonephritis is commonly caused by:

Bacterial infection of medullary interstitium

All of the following are common characteristics of the nephrotic syndrome except:

Hematuria and pyuria

Which of the following conditions is a characterisitic finding in patients with obstructive renal disease?

Azotemia

Whewellite and weddellite kidney stones are composed of:

Calcium oxalate

Which of the following abnormal crystals is often associated with formation of renal calculi?

cystine

Which statement about renal calculi is true?

Calcium oxalate and calcium phosphate account for about three-fourths of all stones