Detecting early oral cancer: narrowband imaging system observation of the oral mucosa microvasculature

NBI comprising monitor, NBI light source, image processor, conventional light source and keyboard.

IPCL classification. Normal IPCL (type I) appear with both waved arms together, as a waved line. At dilation, IPCL (type II) have a similar shape to type I, but their calibre is notably increased compared with others far from the lesion. Elongation (IPCL type III) can be visualized as a simple increase in length or as tangled lines due to the severe increase in length. Generally, elongated IPCL are accompanied by dilation. IPCL type IV is characterized by large vessels with no loops at the terminal branches due to the progression of carcinogenesis which leads to dilation and elongation of the loops and finally their destruction.

IPCL type in normal mucosa. All normal cases presented only IPCL type I.

IPCL in non-neoplastic lesions. Only types II and III were found. Destruction of the capillary loops was not observed.

IPCL types in SCC. The absence of type I and the predominance of types III and IV were observed.

Comparison between conventional and NBI images. (A) Conventional image. Normal mucosa. (B) NBI image from normal mucosa. IPCL regularly organized, can be well visualized. (C) Conventional image. Aphtha. It is difficult to observe the structures due to the pinkish colour. (D) NBI image from image C. Presence of dilated IPCL still organized around the ulcer. Scattered brown spots are clearly observed due to the different contrast from the background mucosa. (E) Conventional image. Lichen planus. (F) Lichen planus. The lesion can be better recognized in the NBI image. (G) Magnification of image F. The presence of abnormal changes and irregular organization of IPCL can be seen. These features made this lesion difficult to distinguish from neoplastic lesions. (H) Conventional image. Leukoplakia. (I) NBI image. Leukoplakia. IPCL visualized around the hyperplasia can be clearly differentiated from surrounding mucosa. (J) Magnified view from image I. IPCL cannot be seen within the hyperplasia area. Dilated and elongated IPCL are still in a regular distribution. (K) Conventional image. SCC. (L) NBI illumination from SCC lesion. Yellow arrow shows a well-demarcated brownish area. (M) Magnified view from the brownish area in image L. In this case, the brownish area presented hyperplasia and several IPCL changes, very different from non-neoplastic lesions. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of the article.)