ASCP Clinical Microscopy 2

Question 1

Which urinary crystal is pathognomonic for cystinuria?

Accepted Answer

Flat hexagonal (benzene ring-shaped) crystals

Answer

Cystine crystals in urine appear as flat, colorless hexagonal plates (benzene ring shape) and are pathognomonic for cystinuria — an autosomal recessive disorder causing defective renal tubular transport of cystine, ornithine, lysine, and arginine.

Question 2

On a peripheral blood smear, target cells (codocytes) are most commonly associated with:

Accepted Answer

Liver disease, thalassemia, hemoglobin C disease, and post-splenectomy

Answer

Target cells have excess membrane relative to hemoglobin content, creating a bull's-eye appearance. They are classic for liver disease (altered lipid composition), thalassemia, hemoglobin C or SC disease, and post-splenectomy states.

Question 3

Wright-Giemsa stain produces its polychromatic differential staining because it contains:

Accepted Answer

A mixture of acidic (eosin) and basic (methylene blue) dyes that react with acidic and basic cellular components

Answer

Wright-Giemsa is a Romanowsky stain containing eosin (acidic, orange-red, staining hemoglobin and eosinophilic granules) and methylene blue or azure B (basic, blue-purple, staining nuclei and basophilic granules). Together they produce the polychromatic differential staining of blood cells.

Question 4

Hypersegmented neutrophils (5 or more lobes in more than 5% of neutrophils, or any neutrophil with 6 or more lobes) are most characteristic of:

Accepted Answer

Megaloblastic anemia (B12 or folate deficiency)

Answer

Hypersegmented neutrophils are a hallmark of megaloblastic anemia, reflecting impaired DNA synthesis (from B12 or folate deficiency) that delays nuclear division relative to cytoplasmic maturation, resulting in larger cells with more nuclear segments.

Question 5

Schistocytes on a peripheral blood smear are most consistent with:

Accepted Answer

Microangiopathic hemolytic anemia (MAHA) such as TTP, HUS, or DIC

Answer

Schistocytes (red cell fragments, helmet cells) form when red cells are mechanically sheared by fibrin strands in microthrombi or damaged endothelium. They are pathognomonic for microangiopathic hemolytic anemia (MAHA): TTP, HUS, DIC, malignant hypertension, and HELLP syndrome.

ASCP Practice Test

ASCP Practice Test

ASCP Clinical Microscopy 2