Narrow-band imaging (NBI) for improving the assessment of vocal fold leukoplakia and overcoming the umbrella effect

Abstract

BackgroundIt is crucial to find a balance between functional and oncological outcome when choosing an adequate method for the management of vocal fold leukoplakia. Therefore, a detailed examination is a milestone in the decision-making process.AimTo examine whether narrow-band imaging (NBI) can be helpful in vocal fold assessment in the case of leukoplakia and how to overcome the “umbrella effect”- understood as the submucosal vascular pattern hidden under the plaque.Material and methodsProspective cohort of 41 consecutive patients. Inclusion criteria: vocal fold leukoplakia, no previous procedures (surgery, radiotherapy), and preoperative endoscopy with an optical filter for NBI. Two groups: “suspicious” and “normal”, according to the submucosal microvascular pattern of peripheral regions of the mucosa surrounding the plaque, were distinguished. Patients were qualified for a full-thickness or partial-thickness biopsy, respectively. Criteria defining suspected characters were well-demarcated brownish areas with scattered brown spots corresponding to type IV, Va, Vb, and Vc NI classifications.ResultsIn 22/41 (53.7%) patients with “suspected” microvascular pattern, full-thickness biopsy was performed. Moderate and severe dysplasia was revealed in 15 type IV and 7 type Va NI patients. In 19/41 (46.3%) patients with proper NBI vessel pattern treated by partial-thickness biopsy, hyperkeratosis was diagnosed. There was a strong correlation between the NBI pattern and final histology: Chi2 (2) = 41.0 (p = 0.0000).ConclusionThe results demonstrate that NBI endoscopic assessment of the submucosal microvascular pattern of mucosa surrounding the plaque can be an effective method to categorise the risk in vocal fold leukoplakia prior to treatment.

Correlating laryngoscopic appearance of laryngeal lesions with histopathology

“…However, the limitations of NBI are the same as that for WLL in being able to discern the subepithelial vasculature. With significant overlying laryngeal keratosis, there is an umbrella effect that prevents visualization of the subepithelial microvascular pattern by the white plaque . In this retrospective pilot study there were at least five cases of hyperkeratotic plaque that prevented visualization of underlying subepithelial vasculature, whereas all five lesions were reported as having severe high‐grade dysplasia.…”

“…WLL coupled with either contact endoscopy or narrow band imaging (NBI) have increased the sensitivity of detecting laryngeal microvascularity . In NBI, the alterations of subepithelial vasculature seen in dysplasia and malignancy are classified as type IV and type V microvascular patterns that appear as brown spots in an area of slight brown tinge . These brown spots are due to changes in intraepithelial papillary capillary loops found underneath the basement membrane of epithelium .…”

Clinical utility and effectiveness of a training programme in the application of a new classification of narrow‐band imaging for vocal cord leukoplakia: A multicentre study

“…However, different observation results in the diagnosis of vocal cord leukoplakia have been reported . The reason for this inconsistency may lie in the fact that the vocal cord surface is generally covered with white patches, which may then affect the appearance of the IPCL on the mucosal surface in an “umbrella effect” that leads to significantly inconsistent results among different researchers on the basis of different emphases and angles. Based on the previous laryngeal NBI classification, we further subdivided the appearances under NBI endoscopy and proposed a new NBI endoscopy classification for the diagnosis of vocal cord leukoplakia.…”

The usefulness of narrow band imaging in the assessment of laryngeal papillomatosis

“…In the presented paper, we focused on the intraoperative use of narrow-band imaging (NBI) in patients suffering from RRP. NBI has been characterized by high sensitivity, specificity, negative predictive value and positive predictive value in the detection of precancerous and cancerous lesions of head and neck region in several studies [ 12 , 13 , 14 ]. However, there have been no previous reports of the intraoperative use of NBI in a significant group of RRP patients.…”