A 32-year-old woman from rural Maharashtra presents to the gynecology clinic with abnormal vaginal bleeding for 3 months. She is sexually active, married at age 18, and has never undergone cervical screening. On examination, the cervix appears grossly normal. Pap smear shows atypical squamous cells of undetermined significance (ASC-US). HPV testing is positive for high-risk HPV-16. What is the most appropriate next step in management?

Explanation

## Management of ASC-US with High-Risk HPV Positivity **Key Point:** ASC-US with high-risk HPV positivity (HPV-16/18) is a high-risk finding that mandates colposcopy with cervical biopsy to exclude CIN 2/3 or invasive disease. ### Rationale for Colposcopy ASC-US represents cytologic ambiguity, but when paired with **high-risk HPV positivity**, the risk of underlying CIN 2/3 is approximately 20–30%. HPV-16 is the most oncogenic type and is present in ~50% of cervical cancers. This combination warrants direct visualization and tissue diagnosis. **Clinical Pearl:** HPV-16 positivity in the setting of ASC-US is NOT a low-risk finding; it is equivalent to a cytologic diagnosis of LSIL (low-grade squamous intraepithelial lesion) in terms of management urgency. ### Why Colposcopy? Colposcopy allows: - Visual assessment of the transformation zone - Application of acetic acid to identify acetowhite lesions - Directed biopsy of suspicious areas - Accurate grading of CIN (1, 2, or 3) or exclusion of invasive disease **High-Yield:** The 2019 ASCCP guidelines recommend colposcopy for all ASC-US cases with high-risk HPV positivity, regardless of age (with rare exceptions for women <25 years in certain settings). ### Colposcopy Findings & Interpretation | Finding | Appearance | CIN Risk | |---------|-----------|----------| | Normal | Pink, fine vessels, no acetowhite change | Low | | Minor abnormality | Faint acetowhite, fine punctation | CIN 1 | | Major abnormality | Dense acetowhite, coarse punctation, mosaicism | CIN 2/3 | | Invasive features | Irregular vessels, ulceration, exophytic mass | Invasive cancer | **Clinical Pearl:** If colposcopy is satisfactory and shows no major abnormalities, cervical biopsy may be deferred; however, given HPV-16 positivity and ASC-US cytology, a biopsy is prudent to exclude CIN 2/3. [cite:ASCCP 2019 Guidelines, Park 26e Ch 12]