Classification of nasopharyngeal microvessels detected by narrow band imaging endoscopy and its role in the diagnosis of nasopharyngeal carcinoma.

ABSTRACT

CONCLUSIONS: The new NBI classification of nasopharyngeal mucosal microvessels was helpful in differential diagnosis for benign and malignant lesions of the nasopharyngeal region. NBI endoscopy facilitates the detection of superficial nasopharyngeal lesions and might enable early diagnoses of NPC. OBJECTIVES: To propose a new microvessel diagnostic classification using narrow band imaging (NBI) endoscopy and to investigate the role of an NBI classification in the diagnosis of nasopharyngeal carcinoma (NPC). METHODS: Between January 2009 and December 2010, a total of 290 patients with a suspected nasopharyngeal tumor were enrolled in this study. The NBI endoscopic system was used to examine the nasopharynx. Each lesion was observed by NBI endoscopy and judged according to the detailed morphologic findings of epithelial microvessels. The superficial microvessel patterns were classified into five types (types I-V). The diagnostic effectiveness of NBI for benign and malignant nasopharyngeal lesions was evaluated. RESULTS: Approximately 93.5% (29/31) of lymphoid hyperplasia appeared as the type II microvessel pattern under NBI endoscopy, whereas 96.2% (51/53) of nasopharyngeal radiation-induced inflammation exhibited the type III or IV microvessel pattern. The characteristics of NPC under NBI endoscopy mainly appeared as a type V microvessel pattern (79.5%, 167/210), and the sensitivity, specificity, predictive value (PPV), and negative predictive value (NPV) of type V in the diagnosis of NPC were 79.5%, 91.3%, 96.0%, and 62.9%, respectively. NBI endoscopy could significantly improve the detection of superficial lesions (χ2 = 12.789, p = .000).