When to perform Endocervical Curettage (ECC) versus cone biopsy?

When to Perform Endocervical Curettage (ECC) vs Cone Biopsy

Cone biopsy is indicated when cervical biopsy is inadequate to define invasiveness, when accurate assessment of microinvasive disease is required, or when there is suspicion of adenocarcinoma in situ affecting the endocervical canal; ECC should be added to colposcopy as clinically indicated, particularly when colposcopy is unsatisfactory, when high-grade cytology is present without visible lesion, or in women aged 46 years or older with high-risk cytology. 1

Primary Indications for Cone Biopsy

Cone biopsy (conization) is the definitive diagnostic procedure in the following scenarios:

• Inadequate cervical biopsy that cannot define the presence or depth of invasiveness 1
• Microinvasive disease requiring accurate assessment of invasion depth and lateral extension 1
• Suspected or confirmed adenocarcinoma in situ (AIS), as these lesions affect the endocervical canal which is difficult to sample with standard cytology or biopsy 1
• Unsatisfactory colposcopy where the squamocolumnar junction or upper limit of the lesion cannot be visualized 1, 2
• Positive endocervical curettage showing CIN 2,3 or AIS 1, 2
• Persistent high-grade cytology (HSIL) for 24 months without histologic confirmation of CIN 2,3 1

Cold knife conization (CKC) is the preferred method of diagnostic excision, though loop electrosurgical excision procedure (LEEP) is acceptable if adequate margins and proper orientation are obtained 1

When to Add ECC to Colposcopy

ECC should be performed in specific clinical situations, not routinely:

Strong Indications for ECC:

• Unsatisfactory colposcopy where the transformation zone cannot be fully visualized 1, 2
• High-grade cytology (HSIL or AGC) without corresponding colposcopic findings 1, 3
• Women aged 46 years or older referred after high-grade cytology, as this population has the highest diagnostic yield 4
• Atypical glandular cells (AGC) on cytology, as part of initial evaluation 1
• Before any ablative procedure for CIN to ensure no endocervical disease is present 2

Limited Utility Situations:

• Satisfactory colposcopy with visible lesion adequately biopsied—ECC adds minimal diagnostic value in routine cases 4, 3
• ECC increases diagnostic yield of CIN 2+ in only 1.01% of colposcopically guided biopsies, meaning 99 ECC procedures are needed to detect one additional CIN 2+ case 4
• However, even with satisfactory colposcopy, ECC detected the sole diagnosis of CIN 2+ in 5.5% of cases in one study, including one invasive cancer 3

Critical Distinctions Between ECC and Cone Biopsy

ECC is a sampling procedure that scrapes the endocervical canal to detect disease not visible at colposcopy, while cone biopsy is an excisional procedure that removes a cone-shaped portion of cervix including the transformation zone and endocervical canal 1

Limitations of ECC:

• Negative ECC does not exclude disease: In adenocarcinoma in situ, residual disease was found in 67% of patients with negative ECC 5
• Cannot assess depth of invasion or provide adequate tissue for staging microinvasive disease 1
• Poor specificity when colposcopy is satisfactory 1

When ECC Findings Mandate Cone Biopsy:

• Positive ECC showing CIN 2,3 or AIS requires diagnostic excisional procedure 1, 2
• ECC showing any grade of CIN with unsatisfactory colposcopy 2
• Discordance between high-grade cytology and negative colposcopy/biopsy with positive ECC 1, 3

Special Populations

Pregnant Women:

• ECC is unacceptable in pregnancy due to risk of complications 1
• Cone biopsy is also unacceptable unless invasive cancer is suspected based on cytology, colposcopy, or biopsy 1

Fertility-Sparing Management:

• Cone biopsy with negative margins (preferably non-fragmented specimen with 3-mm negative margins) is the fertility-sparing option for stage IA1 cervical cancer without LVSI 1
• Women of reproductive age should be counseled about increased preterm birth risk (70% increase) before LEEP or cone biopsy 2

Practical Algorithm

For abnormal cytology with satisfactory colposcopy:

• Perform colposcopically directed biopsy of visible lesions 1
• Add ECC if patient is ≥46 years old with high-grade cytology 4
• Consider ECC if high-grade cytology but low-grade or no visible lesion 3

For abnormal cytology with unsatisfactory colposcopy:

• Perform ECC at time of colposcopy 1, 2
• If ECC positive for CIN 2,3 or AIS, proceed to diagnostic cone biopsy 1, 2

For atypical glandular cells (AGC):

• Perform colposcopy with ECC in all cases 1
• If AIS suspected or confirmed, proceed to cone biopsy for definitive diagnosis and treatment 1, 5

Common Pitfalls to Avoid

• Do not rely on negative ECC to exclude adenocarcinoma in situ—67% of patients with negative ECC had residual disease on subsequent excision 5
• Do not perform routine ECC in young women with satisfactory colposcopy and low-grade cytology—yield is only 2.8% 3
• Do not substitute ECC for cone biopsy when microinvasion assessment is needed—ECC cannot determine depth of invasion 1
• Do not omit ECC before ablative procedures—undetected endocervical disease will be undertreated 2