CT Non-Gynecologic Cytology 2 — Questions and Answers
Question 1: According to The Paris System for Reporting Urinary Cytology, which nuclear-to-cytoplasmic (N:C) ratio threshold defines a high-grade urothelial carcinoma (HGUC) cell?
- >0.3
- >0.5
- >0.7 (Correct answer)
- >0.9
Correct answer: >0.7
The Paris System defines HGUC cells as having an N:C ratio greater than 0.7, along with hyperchromasia and irregular nuclear membranes.
Question 2: Decoy cells in urine cytology mimic high-grade urothelial carcinoma but are caused by infection with which organism?
- Cytomegalovirus (CMV)
- BK polyomavirus (Correct answer)
- Herpes simplex virus
- Human papillomavirus (HPV)
Correct answer: BK polyomavirus
BK polyomavirus infects urothelial cells creating 'decoy cells' with smudgy intranuclear inclusions that mimic HGUC, most commonly in immunocompromised patients.
Question 3: Which preparation method is preferred for cerebrospinal fluid (CSF) cytology to maximize cellular recovery from a hypocellular specimen?
- Conventional smear preparation
- ThinPrep liquid-based cytology
- Cytocentrifugation (cytospin) (Correct answer)
- Cell block preparation
Correct answer: Cytocentrifugation (cytospin)
Cytocentrifugation concentrates sparse cells from a large fluid volume onto a small defined area of the slide, maximizing cell recovery in typically hypocellular CSF.
Question 4: Psammoma bodies identified in a serous pleural or peritoneal effusion are most characteristically associated with which malignancy?
- Epithelioid mesothelioma
- Metastatic small cell carcinoma
- Metastatic papillary serous carcinoma of the ovary (Correct answer)
- Metastatic hepatocellular carcinoma
Correct answer: Metastatic papillary serous carcinoma of the ovary
Psammoma bodies (concentrically laminated calcified structures) are a hallmark of papillary serous carcinoma of the ovary metastasizing to peritoneal or pleural cavities.
Question 5: In pleural effusion cytology, which stain is used to distinguish mucin-secreting adenocarcinoma cells from reactive mesothelial cells?
- Periodic acid-Schiff (PAS)
- Mucicarmine or Alcian blue (pH 2.5) (Correct answer)
- Oil red O
- Perl's Prussian blue
Correct answer: Mucicarmine or Alcian blue (pH 2.5)
Mucicarmine and Alcian blue (pH 2.5) stain intracytoplasmic epithelial mucin in adenocarcinoma cells, which is absent in mesothelial cells.
Question 6: Which cytologic feature of mesothelial cells in effusions helps distinguish them as reactive rather than malignant mesothelioma?
- Two-toned cytoplasm with dense inner and pale peripheral zones (Correct answer)
- Large prominent nucleoli
- Cell-in-cell (cannibalism) pattern
- Papillary clusters with nuclear crowding
Correct answer: Two-toned cytoplasm with dense inner and pale peripheral zones
The characteristic two-toned cytoplasm (dense ectoplasm and pale endoplasm) is a feature of benign/reactive mesothelial cells and is less prominent in malignant mesothelioma.
Question 7: A urine cytology specimen from a 65-year-old male shows cells with hyperchromatic, irregular nuclei, N:C ratio of 0.8, and coarsely clumped chromatin. What is the most appropriate Paris System category?
- Negative for high-grade urothelial carcinoma (NHGUC)
- Atypical urothelial cells (AUC)
- Suspicious for high-grade urothelial carcinoma (SHGUC)
- High-grade urothelial carcinoma (HGUC) (Correct answer)
Correct answer: High-grade urothelial carcinoma (HGUC)
An N:C ratio >0.7 combined with hyperchromasia and irregular nuclear membranes meets The Paris System criteria for HGUC.
CT Non-Gynecologic Cytology 2
According to The Paris System for Reporting Urinary Cytology, which nuclear-to-cytoplasmic (N:C) ratio threshold defines a high-grade urothelial carcinoma (HGUC) cell?