What are the indications for colposcopy?

Indications for Colposcopy

Colposcopy is indicated for women with ASC-H, LSIL (in non-adolescents), HSIL, all categories of atypical glandular cells (AGC), adenocarcinoma in situ (AIS), and ASC-US with positive high-risk HPV testing. 1

Primary Indications by Cytology Result

ASC-US (Atypical Squamous Cells of Undetermined Significance)

• HPV-positive ASC-US: Immediate colposcopy is indicated 1, 2
• HPV-negative ASC-US: Colposcopy is NOT indicated; repeat cytology at 12 months instead 1
• When HPV testing unavailable: Either immediate colposcopy OR repeat cytology at 6-month intervals until 2 consecutive negative results 1
• Repeat cytology showing ASC-US or greater: Refer to colposcopy 1

Important exception: Adolescents (≤20 years) with ASC-US should NOT undergo colposcopy; annual cytology is recommended instead 1

ASC-H (Atypical Squamous Cells, Cannot Exclude HSIL)

• All women with ASC-H require immediate colposcopy regardless of HPV status 1
• This carries significantly higher risk than ASC-US, with substantial rates of underlying CIN 2,3 1

LSIL (Low-Grade Squamous Intraepithelial Lesion)

• Non-adolescent women: Colposcopy is preferred 1
• Adolescents (≤20 years): Annual cytology instead; colposcopy only if HSIL develops at 12 months or ASC-US or greater at 24 months 1
• Pregnant women: Colposcopy is preferred but may be deferred until 6 weeks postpartum 1

HSIL (High-Grade Squamous Intraepithelial Lesion)

• Immediate colposcopy with endocervical assessment OR immediate loop electrosurgical excision are both acceptable 1
• HSIL carries 53-66% risk of CIN 2 or greater and approximately 2% risk of invasive cancer 1
• Pregnant women: Colposcopy by experienced colposcopist; biopsy only if CIN 2,3 or cancer suspected 1

Atypical Glandular Cells (AGC) - All Subcategories

• Colposcopy with endocervical sampling is mandatory for ALL AGC categories 1, 3
• Endometrial sampling required for women ≥35 years or younger women with unexplained vaginal bleeding or chronic anovulation 1, 3
• AGC carries 32.3% risk of malignant lesions and 20.6% risk of pre-malignant lesions 4
• Atypical endometrial cells: Endometrial and endocervical sampling first; colposcopy if no endometrial pathology identified 1

Adenocarcinoma In Situ (AIS)

• Immediate colposcopy with endocervical sampling and endometrial sampling (if ≥35 years) 1
• Diagnostic excisional procedure typically required 3

Secondary Indications

Persistent Abnormalities During Follow-Up

• Persistent ASC-US or greater on repeat cytology after initial ASC-US 1
• Positive HPV test at 12-month follow-up after initial negative HPV with ASC-US 1
• HSIL persisting for 24 months without identified CIN 2,3 requires diagnostic excisional procedure 1

Post-Colposcopy Surveillance

• High-grade colposcopic lesion identified during observation 1
• HPV-positive patients with AGC who had no initial CIN or glandular neoplasia: repeat at 6 months, refer to colposcopy if positive 1, 3

Special Population Considerations

Pregnancy

• Colposcopy can be deferred until 6 weeks postpartum for ASC-US and LSIL in low-risk patients 1
• Immediate colposcopy required for HSIL, ASC-H, and AGC 1
• Endocervical curettage is absolutely contraindicated in pregnancy 1
• Colposcopy should be performed by experienced colposcopist familiar with pregnancy-related changes 1

Adolescents (≤20 Years)

• Colposcopy is NOT indicated for ASC-US or LSIL 1
• HPV testing should not be performed in adolescents with ASC-US or LSIL 1
• High rates of spontaneous clearance make aggressive evaluation unnecessary and potentially harmful 1

Immunosuppressed Women (HIV-Infected, Transplant Recipients)

• Managed identically to general population for colposcopy indications 1
• However, more frequent screening intervals are recommended 2

Critical Caveats

When Colposcopy is NOT Indicated

• Negative HPV with ASC-US: Repeat cytology at 12 months, not colposcopy 1, 2
• Adolescents with ASC-US or LSIL: Annual cytology surveillance 1
• Normal cytology with positive HPV in women ≥30 years: Repeat co-testing at 12 months, not immediate colposcopy 1

Quality Requirements

• Endocervical sampling is preferred when no lesions identified or unsatisfactory colposcopy 1
• Satisfactory colposcopy requires visualization of entire transformation zone 5
• Normal colposcopy with low-grade smear has very low risk of high-grade disease (negative predictive value is high) 5

Common Pitfalls to Avoid

• Do not perform colposcopy for all ASC-US without HPV triage—this leads to unnecessary procedures 1, 2
• Do not defer colposcopy for ASC-H—this carries high risk regardless of HPV status 1
• Do not omit endometrial sampling in women ≥35 years with AGC—7% harbor significant endometrial pathology 1, 3
• Do not perform endocervical curettage in pregnant women—this is absolutely contraindicated 1