ASCP Urinalysis and Body Fluids 2 — Questions and Answers
Question 1: Normal CSF glucose is approximately what percentage of simultaneous serum glucose?
- 20–30%
- 60–70% (Correct answer)
- 90–100%
- 10–15%
Correct answer: 60–70%
Normal CSF glucose is 60–70% of serum glucose; values below 45 mg/dL or <50% of serum suggest bacterial meningitis or other pathology.
Question 2: Red blood cells in CSF that do NOT lyse (xanthochromia present) after centrifugation indicate:
- Traumatic tap
- Subarachnoid hemorrhage (Correct answer)
- Normal finding in elderly
- Viral meningitis
Correct answer: Subarachnoid hemorrhage
Xanthochromia (yellow CSF supernatant) from oxyhemoglobin and bilirubin indicates subarachnoid hemorrhage, not a traumatic tap.
Question 3: A pleural fluid LDH >200 IU/L and pleural/serum LDH ratio >0.6 classifies the fluid as:
- Transudate
- Exudate (Correct answer)
- Chylous effusion
- Normal pleural fluid
Correct answer: Exudate
Light's criteria classify pleural fluid as an exudate if LDH >200, LDH ratio >0.6, or protein ratio >0.5, indicating inflammation or malignancy.
Question 4: Which crystal found in joint fluid under polarized light appears yellow when parallel to the compensator and is seen in gout?
- Calcium pyrophosphate crystals (weakly positive birefringence)
- Monosodium urate crystals (strongly negative birefringence) (Correct answer)
- Cholesterol crystals
- Calcium oxalate crystals
Correct answer: Monosodium urate crystals (strongly negative birefringence)
Monosodium urate crystals are strongly negatively birefringent, appearing yellow when parallel and blue when perpendicular to the slow vibration axis.
Question 5: Semen analysis showing <10 million motile sperm per mL is classified as:
- Normal
- Oligospermia with asthenospermia (Correct answer)
- Azoospermia
- Hyperspermia
Correct answer: Oligospermia with asthenospermia
WHO criteria define oligospermia as <16 million sperm/mL; combined low count and reduced motility (asthenospermia) are common in male factor infertility.
Question 6: A peritoneal fluid with >250 PMN cells/µL is diagnostic of:
- Transudative ascites
- Spontaneous bacterial peritonitis (SBP) (Correct answer)
- Malignant ascites
- Cirrhotic ascites without infection
Correct answer: Spontaneous bacterial peritonitis (SBP)
A PMN count ≥250 cells/µL in ascitic fluid meets diagnostic criteria for spontaneous bacterial peritonitis requiring empiric antibiotic treatment.
ASCP Urinalysis and Body Fluids 2
Normal CSF glucose is approximately what percentage of simultaneous serum glucose?