cervical dysplasia

Cervical dysplasia results from HPV-driven disruption of the normal maturation of squamous epithelium at the cervical transformation zone (squamocolumnar junction), the site most vulnerable to HPV infection and metaplasia. High-risk HPV E6 and E7 oncoproteins inactivate p53 and Rb tumor suppressor proteins, respectively, leading to uncontrolled cell cycle progression and genomic instability.

Histologic grading (CIN): - CIN I: mild dysplasia, lower third of epithelium involved; often regresses spontaneously (low-grade lesion, LSIL on cytology) - CIN II: moderate dysplasia, two-thirds of epithelium involved (high-grade, HSIL) - CIN III: severe dysplasia/carcinoma in situ, full-thickness involvement without stromal invasion (HSIL)

Screening is via Pap smear (cytology) with HPV co-testing in appropriate age groups (ASCCP guidelines). Abnormal Pap results (ASC-US, LSIL, HSIL) are triaged based on age and HPV status, often followed by colposcopy with directed biopsy for definitive histologic diagnosis.

Management depends on grade and patient factors: - CIN I: often observed (high spontaneous regression rate, especially in young women) - CIN II/III: typically treated with excisional procedures like LEEP (loop electrosurgical excision procedure) or cold-knife conization, or ablative therapy (cryotherapy) in select cases

Risk factors include multiple sexual partners, early coitarche, immunosuppression (e.g., HIV), smoking, and lack of HPV vaccination. HPV vaccination (Gardasil) targeting types 6, 11, 16, 18 (and additional types in nonavalent vaccine) significantly reduces risk of dysplasia and cervical cancer.

If untreated, CIN III has significant potential to progress to invasive squamous cell carcinoma of the cervix, though progression takes years, allowing effective screening to prevent cancer through early detection and treatment.