Diagnostic utility of narrow-band imaging endoscopy for pharyngeal superfi cial carcinoma

摘要

AIM: To investigate the endoscopic features of pharyngeal superfi cial carcinoma and evaluate the utility of narrow-band imaging (NBI) for this disease. METHODS: In the present prospective study, 335 patients underwent conventional white light (CWL) en-doscopy and non-magnifi ed/magnifi ed NBI endoscopy, followed by an endoscopic biopsy, for 445 superfi cial lesions in the oropharynx and hypopharynx. The macroscopic appearance of superfi cial lesions was categorized as either elevated (< 5 mm in height), flat, or depressed (not ulcerous). Superficial carcinoma (SC) was defi ned as a superfi cial lesion showing high-grade dysplasia or squamous cell carcinoma on histology. The color, delineation, and macroscopic appearances of the lesions were evaluated by CWL endoscopy. The ratio of the brownish area/intervascular brownish epithelium (IBE), as well as microvascular proliferation, dilation, and irregularities, was determined by non-magnifi ed/ magnifi ed NBI endoscopy. An experienced pathologist who was unaware of the endoscopic fi ndings made the histological diagnoses. By comparing endoscopic fi ndings with histology, we determined the endoscopic features of SC and evaluated the diagnostic utility of NBI. RESULTS: The 445 lesions were divided histologically into two groups: a non-SC group, including non-neoplasia and low-grade dysplasia cases, and an SC group. Of the 445 lesions examined, 333 were classified as non-SC and 112 were classif ied as SC. There were no significant differences in age, gender, or the location of the lesions between the patients in the two groups. The mean diameter of the SC lesions was signif icantly greater than that of non-SC lesions (11.0 ± 7.6 mm vs 4.6 ± 3.6 mm, respectively, P < 0.001). Comparisons of CWL endoscopy fi ndings for SC and non-SC lesions by univariate analysis revealed that the incidence of redness (72% vs 41%, respectively, P < 0.001) and a flat or depressed type of lesion (58% vs 44%, respectively, P = 0.013) was significantly higher in the SC group. Using non-magnifi ed NBI endoscopy, the incidence of a brownish area was signifi cantly higher for SC lesions (79% vs 57%, respectively, P < 0.001). On magnifi ed NBI endoscopy, the incidence of IBE (68% vs 33%, P < 0.001) and microvascular proliferation (82% vs 51%, P < 0.001), dilation (90% vs 76%, P =0.002), and irregularity (82% vs 31%, P < 0.001) was also signifi cantly higher for the SC compared with the non-SC lesions. Multivariate analysis revealed that the incidence of redness (P = 0.022) on CWL endoscopy and IBE (P < 0.001) and microvascular irregularities (P < 0.001) on magnif ied NBI endoscopy was signif icantly higher in SC than non-SC lesions. Redness alone exhibited signifi cantly higher sensitivity and signifi cantly lower specifi city for the diagnosis of SC compared with redness plus IBE and microvascular irregularities (72% vs 52%, P = 0.002; and 59% vs 92%, P < 0.001, respectively). The accuracy of redness plus IBE and irregularities for the diagnosis of SC was signifi cantly greater than using redness alone (82% vs 62%, respectively, P < 0.001). CONCLUSION: Redness, IBE, and microvascular irregularities appear to be closely related to SC lesions. Magnifi ed NBI endoscopy may increase the diagnostic accuracy of CWL endoscopy for SC.