Question
A Papanicolaou (Pap) smear from a 35-year-old woman shows sheets of cervical squamous epithelial cells that have lost their normal polarity and stratification. The cells display marked nuclear hyperchromasia, irregular nuclear contours, and increased mitotic figures confined above the basement membrane. Which cellular process best explains these cytologic findings?
| A. |
Dysplasia
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| B. |
Metaplasia
|
| C. |
Hypertrophy
|
| D. |
Invasive Carcinoma
|
Show Answer
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Correct Answer » A
Explanation
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– Architectural disorder: Cells arranged haphazardly, lose maturation from basal layer.
– Cytologic atypia: Enlarged, hyperchromatic nuclei, irregular membranes, ↑ mitoses.
– No basement membrane breach: Lesion confined to epithelium, indicating dysplasia.
Dysplasia & Cervical Intraepithelial Neoplasia (CIN):
Definition: Disordered epithelial growth, pre-malignant, confined to epithelium.
Grading:
– CIN 1: Mild dysplasia, lower ⅓ involved.
– CIN 2: Moderate dysplasia, lower ⅔ involved.
– CIN 3: Severe dysplasia/full-thickness atypia, no invasion.
Etiology: High-risk HPV (16, 18, 31, 33). Oncoproteins E6/E7 inactivate p53/Rb.
Natural History: CIN 1 often regresses; CIN 2/3 has 30% risk of squamous carcinoma without treatment.
Screening: Pap smear detects atypical squamous cells; HPV testing ↑ sensitivity.
Management:
– CIN 1: Observation or ablation if persistent.
– CIN 2/3: Excisional procedures (LEEP/cold-knife cone).
– Reversibility: Potentially reversible if inciting stimulus (e.g., HPV) is cleared.
– Contrast with Carcinoma: Once invasive, carcinoma is not reversible and may metastasize.
Incorrect Options:
– B. Metaplasia – Reversible cell type substitution (e.g., columnar → squamous).
– C. Hypertrophy – ↑ cell size (e.g., muscle growth), no pleomorphism.
– D. Invasive carcinoma – Requires basement membrane penetration, not seen in smears.
