ABPath Cytopathology 2 — Questions and Answers
Question 1: On a cervical Pap smear, which cellular feature is most characteristic of a high-grade squamous intraepithelial lesion (HSIL)?
- Increased nuclear-to-cytoplasmic ratio with hyperchromasia (Correct answer)
- Abundant glycogenated cytoplasm
- Perinuclear halos with mild nuclear enlargement
- Prominent cytoplasmic keratinization only
Correct answer: Increased nuclear-to-cytoplasmic ratio with hyperchromasia
HSIL cells show markedly increased nuclear-to-cytoplasmic ratio, hyperchromasia, and irregular nuclear contours.
Question 2: A thyroid FNA shows follicular cells with nuclear grooves, powdery chromatin, and intranuclear pseudoinclusions. Which diagnosis is most likely?
- Papillary thyroid carcinoma (Correct answer)
- Medullary carcinoma
- Follicular adenoma
- Hashimoto thyroiditis
Correct answer: Papillary thyroid carcinoma
Nuclear grooves, pale powdery chromatin, and intranuclear pseudoinclusions are hallmarks of papillary thyroid carcinoma.
Question 3: Which Bethesda System category for thyroid cytology carries the highest risk of malignancy?
- Malignant (Category VI) (Correct answer)
- Atypia of undetermined significance (Category III)
- Benign (Category II)
- Nondiagnostic (Category I)
Correct answer: Malignant (Category VI)
Category VI (Malignant) has the highest malignancy risk, approaching 97-99%.
Question 4: In a serous effusion, which feature best distinguishes reactive mesothelial cells from adenocarcinoma cells?
- Windows (spaces) between adjacent mesothelial cells (Correct answer)
- Presence of psammoma bodies
- Large three-dimensional cell balls
- Sharp community borders with mucin vacuoles
Correct answer: Windows (spaces) between adjacent mesothelial cells
Intercellular windows created by microvilli are characteristic of benign mesothelial cells.
Question 5: Which immunostain is most useful to confirm mesothelial origin of cells in an effusion?
- Calretinin (Correct answer)
- MOC-31
- TTF-1
- CEA
Correct answer: Calretinin
Calretinin is a sensitive and specific marker of mesothelial differentiation.
Question 6: A urine cytology specimen shows cells with high N/C ratio, hyperchromatic irregular nuclei, and coarse chromatin. This best fits which Paris System category?
- High-grade urothelial carcinoma (Correct answer)
- Negative for high-grade urothelial carcinoma
- Atypical urothelial cells
- Low-grade urothelial neoplasm
Correct answer: High-grade urothelial carcinoma
High N/C ratio with hyperchromasia and coarse chromatin defines high-grade urothelial carcinoma in the Paris System.
Question 7: Which artifact commonly causes air-drying changes on cytology smears?
- Delayed fixation of the smear (Correct answer)
- Overstaining with hematoxylin
- Excessive alcohol fixation
- Prolonged formalin exposure
Correct answer: Delayed fixation of the smear
Air-drying occurs when smears are not promptly fixed, causing nuclear enlargement and loss of detail.
ABPath Cytopathology 2
On a cervical Pap smear, which cellular feature is most characteristic of a high-grade squamous intraepithelial lesion (HSIL)?