Endoscopic diagnosis value of narrow band imaging Ni classification in vocal fold leukoplakia and early glottic cancer.

OBJECTIVES

To explore the diagnostic value and the correlation between histological diagnosis and the Ni classification under narrow band imaging (NBI) for vocal fold leukoplakia (VFL) and early glottic cancer.

METHODS

A total of 91 patients with 119 vocal fold lesions were selected from January 2017 to May 2020. All these patients were subsequently examined by white light imaging (WLI) and NBI endoscopy, and then all lesions were classified by the Ni classification according to the characteristics of intraepithelial papillary capillary loop (IPCL) observed. The gold standard of diagnosis was histopathological results. Eventually, the chi-square and kappa test were applied, respectively, to evaluate the diagnostic value of NBI endoscopy and the consistency of Ni classification and pathological results.

RESULTS

The accuracy and sensitivity of NBI endoscopy were significantly higher than that of WLI endoscopy (P < 0.05). For the diagnosis of precancerous lesions under the NBI, the sensitivity, specificity, positive and negative predictive value were 69.6% (16/23), 90.6% (87/96), 64.0% (16/25) and 92.6% (87/94), which for malignant lesions were 84.4% (65/77), 92.9% (39/42), 95.6% (65/68) and 76.5% (39/51). Moreover, for patients with low-grade intraepithelial neoplasia (mild and moderate dysplasia), type IV lesions accounted for the most (69.6 vs 30.4%; χ = 36.961, P < 0.001). For high-grade intraepithelial neoplasia or carcinoma in situ, type Va lesions were predominant (χ = 30.526, P < 0.001), while type Vb and Vc lesions were dominant in invasive carcinoma (χ = 64.373, P < 0.001). Besides, the kappa test revealed that there was a high consistency between Ni classification and pathological diagnosis (Kappa = 0.667, P < 0.001).

CONCLUSIONS

The Ni classification can improve the diagnosis accuracy of vocal fold lesions which enables clear visualization of mucosal microvasculature. This is essential for the early diagnosis of VFL and early glottic cancer during routine endoscopic examination.