Pap Smear Prior to Conization for CIN 2/3
A Pap smear is not required before performing conization for confirmed high-grade cervical intraepithelial neoplasia (CIN 2/3). The diagnosis of CIN 2/3 is established by colposcopy-directed biopsy, and once histologically confirmed, treatment decisions are based on the biopsy results and colposcopic findings—not on cytology 1.
Rationale for Not Requiring Pre-Conization Cytology
The 2006 ASCCP Consensus Guidelines make clear that management of histologically confirmed CIN 2/3 proceeds directly to treatment without mandating additional cytology 1. The key decision points are:
- Colposcopic adequacy: Whether the colposcopy is satisfactory or unsatisfactory determines the type of excision needed 1
- Histologic confirmation: The biopsy diagnosis of CIN 2/3 is sufficient to proceed with treatment 1
- Prior cytology: The original cytology that prompted colposcopy has already served its screening purpose 1
Treatment Algorithm Based on Colposcopy Findings
For Satisfactory Colposcopy
- Both excision and ablation are acceptable treatment modalities for women with histologically confirmed CIN 2/3 and satisfactory colposcopy 1
- Excisional procedures (LEEP, laser conization, or cold-knife conization) are preferred because they provide tissue for pathologic examination to exclude occult invasive cancer, which occurs in 4-16% of cases 2
For Unsatisfactory Colposcopy
- A diagnostic excisional procedure is mandatory when colposcopy is unsatisfactory 1
- Ablation is unacceptable in this scenario 1
For Recurrent CIN 2/3
- A diagnostic excisional procedure is recommended for women with recurrent CIN 2/3 1
When Cytology Actually Matters in the CIN Management Pathway
Cytology plays a role at different points in the management pathway, but not immediately before conization for confirmed CIN 2/3:
- Initial screening: Cytology identifies patients who need colposcopy 1
- Post-treatment surveillance: Cytology at 4-6 month intervals or HPV testing at 6-12 months is used for follow-up after treatment 1, 2, 3
- CIN 1 management: For histologic CIN 1 (not CIN 2/3), the preceding cytology result influences whether observation versus immediate excision is chosen 1
Critical Pitfalls to Avoid
- Do not delay treatment of confirmed CIN 2/3 to obtain additional cytology—observation with sequential cytology and colposcopy is unacceptable except in special circumstances (pregnancy, adolescents) 1
- Do not confuse the pathway: The cytology-colposcopy-biopsy sequence is for diagnosis; once CIN 2/3 is histologically confirmed, proceed directly to treatment planning 1
- Do not use hysterectomy as primary therapy for CIN 2/3 unless other indications exist 1, 2
Special Consideration: Endocervical Sampling
While a Pap smear is not needed, endocervical sampling (endocervical curettage) is recommended before ablative treatment to ensure no endocervical involvement that would require excision instead 1. This is distinct from cervical cytology and serves to assess the extent of disease 1.