ASCP Clinical Microscopy 3

Question 1

Massive calcium oxalate crystalluria in a patient with high anion gap metabolic acidosis is most concerning for:

Accepted Answer

Ethylene glycol poisoning

Answer

Calcium oxalate crystals in massive amounts, combined with high anion gap metabolic acidosis, high osmol gap, and altered mental status, are characteristic of ethylene glycol (antifreeze) poisoning, where oxalic acid is a toxic metabolite.

Question 2

Döhle bodies in neutrophils on a peripheral blood smear are most commonly seen in:

Accepted Answer

Severe infections, burns, or toxic states

Answer

Döhle bodies are pale blue, oval cytoplasmic inclusions in neutrophils representing lamellar endoplasmic reticulum (aggregated ribosomes or rough ER). They indicate toxic neutrophil changes in severe infections, burns, surgery, pregnancy, or drug toxicity.

Question 3

Which finding on urine microscopy is pathognomonic (diagnostic) of glomerulonephritis?

Accepted Answer

Red blood cell casts

Answer

Red blood cell (RBC) casts are pathognomonic (diagnostic) of glomerulonephritis. They form when RBCs become trapped in the Tamm-Horsfall protein matrix within glomerular capillary loops or tubules, indicating glomerular bleeding.

Question 4

On a stained bone marrow aspirate, a plasma cell is identified by which morphological features?

Accepted Answer

Eccentric nucleus with clock-face chromatin and basophilic cytoplasm with perinuclear hof (clearing)

Answer

Plasma cells have an eccentric round nucleus with coarsely clumped chromatin in a clock-face or cartwheel pattern, deeply basophilic cytoplasm (rich in rough ER for immunoglobulin synthesis), and a clear perinuclear hof (Golgi zone).

Question 5

Trichomonas vaginalis on a wet prep (saline mount) is identified by:

Accepted Answer

Motile, pear-shaped flagellated organisms with jerky tumbling motility

Answer

Trichomonas vaginalis is a flagellated protozoan seen as a motile, pear-shaped (pyriform) organism on wet prep. The characteristic tumbling or rocking motility distinguishes it from non-motile artifacts. Flagella (4 anterior plus 1 recurrent) drive the motility.

ASCP Practice Test

ASCP Practice Test

ASCP Clinical Microscopy 3