Diagnostic utility of narrow-band imaging endoscopy for pharyngeal superficial carcinoma

Figure 2 Representative images of a superficial carcinoma. A: Conventional gastrointestinal endoscopy image revealing a flat and poorly delineated lesion with a slight redness at the piriform sinus of the right hypopharynx (arrows); B: The superficial carcinoma lesion is revealed as a well-demarcated brownish area by non-magnified narrow-band imaging (NBI) endoscopy (arrows); C: Magnified NBI endoscopy visualizes the brownish area of the superficial carcinoma and shows it to be comprised of intervascular brownish epithelium and superficial microvessels of a dark brown color exhibiting dilation, proliferation and irregularities. Arrowheads indicate the demarcation line of the lesion; D: Histology of an endoscopically biopsied superficial carcinoma specimen demonstrating squamous cell carcinoma in situ with keratinization (hematoxylin and eosin stain; original magnification × 50).