Clinical Microscopy Flashcards
6 cards from real ASCP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Clinical Microscopy flashcards as text
Which urinary crystal is pathognomonic for cystinuria?
Answer: Flat hexagonal (benzene ring-shaped) crystals
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.
On a peripheral blood smear, target cells (codocytes) are most commonly associated with:
Answer: Liver disease, thalassemia, hemoglobin C disease, and post-splenectomy
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.
Wright-Giemsa stain produces its polychromatic differential staining because it contains:
Answer: A mixture of acidic (eosin) and basic (methylene blue) dyes that react with acidic and basic cellular components
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.
Hypersegmented neutrophils (5 or more lobes in more than 5% of neutrophils, or any neutrophil with 6 or more lobes) are most characteristic of:
Answer: Megaloblastic anemia (B12 or folate deficiency)
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.
Schistocytes on a peripheral blood smear are most consistent with:
Answer: Microangiopathic hemolytic anemia (MAHA) such as TTP, HUS, or DIC
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.
In CSF analysis, lymphocytic pleocytosis with elevated protein and normal glucose is most consistent with:
Answer: Viral (aseptic) meningitis or early tuberculous meningitis
Viral meningitis classically shows CSF lymphocytic pleocytosis (10–1000 cells/µL, predominantly lymphocytes), mildly elevated protein (50–100 mg/dL), and normal glucose (at least 2/3 of serum glucose). Bacterial meningitis has predominantly PMNs, very high protein, and low glucose.