Endoscopic Vascular Assessment of Cervical Polyps Using Narrow-Band Imaging (NBI): A Prospective Observational Strategy Study to Support Selective Biopsy Decision-Making

Abstract

Objective:

To evaluate whether depth-resolved vascular assessment using narrow-band imaging (NBI) can support selective biopsy decision-making in benign-appearing cervical polyps.

Methods:

A prospective observational pilot study included 30 patients presenting with visible cervical lesions: simple cervical polyps, lobulated polyps, condyloma acuminata, and chronic hypertrophic cervicitis. All lesions were examined using a structured triple-light endoscopic protocol: white-light imaging (WLI), blue-light NBI (410 nm), and green-light NBI (540 nm). Superficial and deep vascular patterns were prospectively assessed and correlated with histopathology. Diagnostic agreement was measured using Cohen's kappa coefficient.

Results:

Distinct and reproducible vascular signatures were observed for each lesion type. Depth-resolved vascular mapping allowed reliable identification of lesions with stable benign architecture, supporting selective rather than routine biopsy. Overall agreement between NBI assessment and histopathology was very high (κ ≈ 1.0). No clinically significant pathology was missed.

Conclusion:

Structured multi-modal NBI assessment may serve as a safe and effective clinical triage strategy for selective biopsy in benign-appearing cervical polyps. This approach has the potential to reduce unnecessary procedures while maintaining diagnostic safety. Larger, controlled studies are warranted.

Introduction

Cervical polyps and other benign-appearing lesions are frequently encountered in gynecologic practice and are often subjected to routine biopsy or excision to rule out malignancy. Most of these lesions are non-neoplastic, resulting in unnecessary procedures, patient anxiety, and increased healthcare costs.

Conventional white-light imaging (WLI) provides limited functional information regarding vascular architecture. Narrow-band imaging (NBI) enhances visualization of mucosal and submucosal microvasculature by exploiting hemoglobin absorption peaks: blue light (410 nm) highlights superficial capillaries, while green light (540 nm) visualizes deeper stromal vessels.

This study evaluates whether a structured, depth-resolved NBI protocol can identify stable vascular patterns indicative of benign lesions and support selective biopsy decision-making.

Materials and Methods

Study Design

Prospective observational study conducted during routine gynecologic endoscopy.

Inclusion Criteria

• Simple cervical polyps

• Lobulated cervical polyps

• Condyloma acuminata

• Chronic hypertrophic cervicitis

Exclusion Criteria

• Colposcopic suspicion of high-grade CIN (CIN 2+)

• Suspicion of invasive malignancy

• Cervical surgery within the last 6 months

Endoscopic Imaging Protocol

All examinations were performed using a Fujifilm endoscopic system with NBI capability. Each lesion was sequentially evaluated using:

White-Light Imaging (WLI): Gross morphology, surface contour, color.

Blue-Light NBI (410 nm): Superficial capillary loops and epithelial microvascular patterns.

Green-Light NBI (540 nm): Deep stromal vessels, vascular symmetry, and feeding patterns.

Vascular Pattern Interpretation

Lesions were prospectively classified based on:

• Organization and regularity of superficial capillaries

• Symmetry and architecture of deep stromal vessels

• Concordance between superficial and deep vascular patterns

Lesions with organized superficial capillaries and symmetric deep vessels were categorized as low-risk.

Histopathology

All lesions underwent targeted biopsy or complete excision per clinical practice. Histopathology served as the reference standard.

Statistical Analysis

Agreement between NBI assessment and histopathology was calculated using Cohen's kappa coefficient.

Results

Distinct vascular patterns were observed across lesion types:

Simple cervical polyps: Thin, linear superficial capillary loops on blue-light NBI; straight, symmetric deep feeding vessels on green-light NBI. Histology confirmed benign endocervical polyps with thin epithelial covering. (Figure 1)

Lobulated cervical polyps: Peripheral superficial loops with organized lobular vascular cores; histology confirmed fibroepithelial expansion without atypia. (Figure 2)

Condyloma acuminata: Central punctate superficial vascular patterns with preserved deep vascular symmetry; histology showed koilocytic changes consistent with HPV lesions. (Figure 3)

Chronic hypertrophic cervicitis: Dilated but non-tortuous superficial capillaries and deep venous congestion; histology showed inflammatory stromal thickening. (Figure 4)

Overall agreement between NBI assessment and histopathology was very high (κ ≈ 1.0). No high-grade dysplasia or malignancy was missed using selective assessment.

Discussion

Structured, depth-resolved NBI provides functional vascular information beyond conventional WLI. Stability and symmetry of both superficial and deep vessels are reliable indicators of benign pathology.

Selective biopsy guided by NBI can reduce unnecessary procedures while maintaining diagnostic safety. This strategy complements, rather than replaces, histopathology by guiding rational decision-making in low-risk lesions.

Limitations: Small sample size and single-operator design. Larger multicenter studies are needed to validate these findings and standardize NBI criteria.

Conclusion

Multi-modal NBI offers a promising, non-invasive strategy for selective biopsy in benign-appearing cervical polyps. Combined with clinical judgment, NBI-based vascular assessment may reduce unnecessary interventions without compromising diagnostic accuracy.

Figures

Figure 1: Simple cervical polyps: Thin, linear superficial capillary loops on blue-light NBI; straight, symmetric deep feeding vessels on green-light NBI. Histology confirmed benign endocervical polyps with thin epithelial covering.

Figure 2: Lobulated cervical polyp—vascular lobules visible in depth-resolved NBI.

Figure 3: Condyloma acuminata—central punctate superficial vessels.

Figure 4: Chronic hypertrophic cervicitis—dilated superficial capillaries and deep venous congestion.

References

1. Gono K, Obi T, Yamaguchi M, et al. Appearance of enhanced tissue microvessels in narrow-band endoscopic imaging. J Biomed Opt. 2004;9(3):568-577.

2. Mitani T, Okamoto S, Kondo Y, et al. Endoscopic diagnosis of cervical lesions using narrow-band imaging: A pilot study. Gynecol Oncol. 2010;118(2):212-218.

3. Arbyn M, Weiderpass E, Bruni L, et al. Estimates of incidence and mortality of cervical cancer in 2018: a worldwide analysis. Lancet Glob Health. 2020;8(2):e191-e203.

4. Uchita H, Kitagawa R, Mitsuhashi N, et al. Narrow-band imaging for cervical intraepithelial neoplasia detection. J Obstet Gynaecol Res. 2015;41(4):569-575.

5. Wright TC, Massad LS, Dunton CJ, et al. 2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests. Am J Obstet Gynecol. 2007;197(4):346-355.

6. Gkegkes ID, Mamais I, Iavazzo C. Cervical polyps: Review of histopathology and clinical management. J Obstet Gynaecol. 2015;35(3):259-263.