HGSIL (High-Grade Squamous Intraepithelial Lesion): Definition, Risk, and Management

HGSIL (also HSIL in Bethesda 2001+) is a cytologic/histologic diagnosis indicating high-grade squamous intraepithelial lesion of the cervix, vagina, vulva, or anus.

Pathology

• Encompasses CIN 2 (moderate dysplasia) and CIN 3 (severe dysplasia / carcinoma in situ).
• Cells show marked nuclear atypia, high N:C ratio, mitotic figures extending to upper epithelium.
• Driven by high-risk HPV (types 16, 18, 31, 33, 45, etc.).

Clinical Significance

• Precancerous – Untreated, ~30–50% of CIN 3 progress to invasive cancer over years.
• Not cancer – Basement membrane intact.

Management (ASCCP Guidelines)

1. Colposcopy with biopsy – Confirm histology.
2. CIN 2 – Excision (LEEP, cold knife cone) or observation (age 21–24) with 6-mo colposcopy.
3. CIN 3 / AIS – Excisional procedure preferred; hysterectomy if recurrent/positive margins.
4. Post-treatment surveillance – Co-testing at 12 & 24 mo, then 3–5 yr.

Prevention

HPV vaccination (9-valent) before sexual debut; regular screening per guidelines.