Microscopic: cells

11 ASCP MLS practice questions on Microscopic: cells, part of Urinalysis and Body Fluids. The first 11 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Hard

   A 44-year-old man has severe left flank pain, and CT shows a 4-mm ureteral stone. His first morning urine: SG 1.032, pH 5.5, protein negative, blood 3+. Sediment: 30-50 RBC/HPF and no casts. A trainee reports 'dysmorphic red cells, suggest glomerular disease' because many of the red cells are small, with sharp, evenly spaced spikes around a regular outline. On review under phase contrast, the red cells all look alike, and there are no ring forms with knob-like blebs and no fragments. The best interpretation is:

   1. ADysmorphic cells; early glomerular disease
   2. BCrenated cells; bleeding from the stone
   3. CAcanthocytes; glomerular bleeding
   4. DGhost cells from lysis in a dilute urine

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   Answer: B · Crenated cells; bleeding from the stone

   In concentrated urine, red cells lose water and crenate: they shrink and develop regular, evenly spaced spikes, and the cells keep a uniform appearance. Dysmorphic red cells from the glomerulus vary in size and shape, with blebs, fragments and ring forms with knobs (acanthocytes), and usually come with proteinuria or red cell casts. Here the urine is hypertonic (SG 1.032), the cells are uniform, protein is negative, there are no casts, and a ureteral stone explains the bleeding. Crenation is an osmotic change and must not be reported as dysmorphism. Phase-contrast review together with the clinical picture separates the two.

   • A: Glomerular dysmorphic cells are irregular, with blebs and fragments, and protein and casts are absent here.
   • C: Acanthocytes are ring forms with knob-like blebs, which are not seen.
   • D: Ghost cells form in dilute urine, but this urine is concentrated (SG 1.032).

2. Question 2 · Medium

   Finding more than two renal tubular epithelial cells per HPF in a fresh urine most suggests:

   1. AVaginal contamination
   2. BNormal bladder shedding
   3. CAcute tubular injury
   4. DRecent catheterization

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   Answer: C · Acute tubular injury

   Renal tubular epithelial (RTE) cells line the nephron, and more than two per HPF points to tubular damage. Causes include acute tubular necrosis from ischemia, toxic drugs such as aminoglycosides, heavy metals, and transplant rejection. Collecting duct cells are cuboidal with an eccentric nucleus, which helps separate them from white cells. RTE cells that absorb filtered lipid become oval fat bodies.

   • A: Vaginal contamination adds squamous cells.
   • B: The bladder sheds urothelial (transitional) cells, not tubular cells.
   • D: Catheterization dislodges clumps of urothelial cells.

3. Question 3 · Medium

   A 66-year-old man who smokes has painless visible hematuria. The sediment shows 50-100 red cells/HPF, all of normal shape, and no casts. Where is the bleeding most likely coming from?

   1. AInjured skeletal muscle
   2. BThe damaged glomerular capillaries
   3. CThe bladder or lower tract
   4. DIschemic renal tubules

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   Answer: C · The bladder or lower tract

   Red cells that pass through damaged glomeruli become deformed (dysmorphic, such as acanthocytes) and often come with red cell casts and proteinuria. Uniform, normally shaped red cells with no casts point to non-glomerular bleeding, most often from the bladder, ureters or prostate. Painless hematuria in an older smoker raises concern for urothelial carcinoma of the bladder. Such patients need urologic evaluation.

   • A: Muscle injury releases myoglobin, which gives a positive blood pad but no red cells.
   • B: Glomerular bleeding gives dysmorphic red cells, often with red cell casts.
   • D: Tubular injury sheds tubular cells and granular casts rather than many intact red cells.

4. Question 4 · Hard

   An unrefrigerated urine is tested 5 hours after collection: specific gravity 1.004, pH 8.0, blood 2+, and 0-2 red cells/HPF with a few ghost cells. The plasma is not hemolyzed and serum CK is normal. What best explains these results?

   1. ARed cells lysed in the dilute, alkaline urine
   2. BAscorbic acid interfering with the blood pad
   3. CMyoglobin released from injured muscle
   4. DHemoglobin from intravascular hemolysis

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   Answer: A · Red cells lysed in the dilute, alkaline urine

   In dilute and alkaline urine, red cells swell and lyse, leaving ghost cells and free hemoglobin. The blood pad detects free hemoglobin by its peroxidase-like activity, so the strip stays positive while few intact cells are counted. The 5-hour delay at room temperature adds to the lysis. Urine should be examined within 2 hours or refrigerated, so a fresh sample tested promptly is the fix.

   • B: Ascorbic acid causes false-negative, not false-positive, blood results.
   • C: Myoglobinuria from muscle injury would come with a raised CK.
   • D: Intravascular hemolysis would leave the plasma pink.

5. Question 5 · Medium

   A sediment contains many oval fat bodies whose droplets show Maltese crosses under polarized light. Which reagent strip result would you most expect with it?

   1. ALeukocyte esterase 3+
   2. BNitrite positive
   3. CBilirubin 3+
   4. DProtein 4+

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   Answer: D · Protein 4+

   Oval fat bodies are renal tubular cells or macrophages that have absorbed lipid filtered through damaged glomeruli. Cholesterol in the droplets gives the Maltese crosses. Lipiduria with heavy proteinuria, often 3.5 g/day or more, is typical of nephrotic syndrome. The sediment and the protein pad should agree, and a mismatch calls for a recheck.

   • A: Leukocyte esterase points to white cells, not fat.
   • B: Nitrite points to bacteria, not lipiduria.
   • C: Bilirubin points to liver or biliary disease.

6. Question 6 · Easy

   Using the ASCP reference ranges, which urine sediment result is abnormal?

   1. A2 hyaline casts/LPF
   2. B4 squamous epithelial cells/HPF
   3. C5 white cells/HPF
   4. D6 red cells/HPF

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7. Question 7 · Easy

   Swollen neutrophils whose granules sparkle with Brownian movement in hypotonic urine are called:

   1. AGhost cells
   2. BClue cells
   3. CGlitter cells
   4. DOval fat bodies

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8. Question 8 · Hard

   A 58-year-old woman started a beta-lactam antibiotic 10 days ago and now has fever, rash and a creatinine of 2.4 mg/dL (212 µmol/L). Urine shows 20-25 white cells/HPF and white cell casts; nitrite is negative and culture has no growth. Which sediment stain best supports the suspected diagnosis?

   1. ASudan III stain for neutral fat
   2. BPrussian blue stain for hemosiderin
   3. CHansel stain for eosinophils
   4. DGram stain for bacteria

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9. Question 9 · Easy

   Many squamous epithelial cells in a midstream urine from a woman most often indicate:

   1. ACarcinoma of the bladder lining
   2. BInfection of the renal pelvis
   3. CVaginal or distal urethral contamination
   4. DInjury to the lining of the renal tubules

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10. Question 10 · Medium

    Adding 2% acetic acid to a urine sediment helps identify red cells because it:

    1. AMakes red cells show a Maltese cross
    2. BLyses red cells but not yeast or oil droplets
    3. CLyses yeast but leaves red cells intact
    4. DStains red cell membranes dark pink

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11. Question 11 · Easy

    In a dilute urine with a low specific gravity, red cells tend to:

    1. AChange into sickle forms
    2. BLose water and shrink into crenated cells
    3. CStack together in rouleaux
    4. DSwell and lyse into ghost cells

    Answer and explanation in LearnFree account