Nobunao Ikehara

Diagnosis of colorectal lesions with the magnifying narrow-band imaging system

BACKGROUND Narrow-band imaging (NBI) emphasizes the surface microvasculature of the GI tract and may help in detecting small neoplasms. OBJECTIVE The aim of this study was to clarify the value of the NBI system in tissue characterization and differential diagnosis. DESIGN A prospective study. SETTING Digestive Disease Center of Showa University Northern Yokohama Hospital. PATIENTS The subjects were 495 patients who, from January 2006 to June 2007, underwent a complete colonoscopic examination. A total of 617 lesions were evaluated in the 495 patients (33 hyperplastic polyps, 532 adenomas, 52 submucosally invasive [T1] cancers). RESULTS Most hyperplastic polyps showed a faint pattern. The vascular patterns of adenomas were mainly the network pattern or the dense pattern. The major vascular patterns of cancers were the irregular pattern and the sparse pattern. The irregular pattern was characteristic for protruded or flat-elevated cancers, whereas the sparse pattern was unique for depressed cancers. When we assumed that the faint pattern was diagnostic for hyperplastic polyps, we could differentiate between neoplastic and non-neoplastic lesions with a sensitivity of 90.9% and a specificity of 97.1%. Likewise, irregular and sparse patterns were assumed to be indices of massively invasive submucosal cancer, the sensitivity was 100%, the specificity was 95.8%, and the accuracy rate was 96.1%. LIMITATIONS This study was performed at a single center. CONCLUSIONS The NBI system was valuable for distinguishing between neoplastic and non-neoplastic lesions, as well as between cancers and adenomas. Vascular pattern analysis can also be a promising tool for determining treatment selection, either endoscopy or surgery.

Efficiency of endocytoscopy in differentiating types of serrated polyps

BACKGROUND Accurate endoscopic criteria are needed to differentiate serrated polyps, including hyperplastic polyp (HP), sessile serrated adenoma/polyp (SSA/P), and traditional serrated adenoma (TSA), because some are precursors of colorectal cancers. OBJECTIVE To determine the endocytoscopic features of each type of serrated polyp, especially the shapes of lumens and nuclei. DESIGN Retrospective study. SETTING Single, tertiary-care referral center. PATIENTS Patients who underwent removal of serrated polyps from May 2005 to December 2012. INTERVENTION Endocytoscopy was performed. Endocytoscopic images were evaluated by assessing the shapes of the lumens and nuclei of the target lesions. MAIN OUTCOME MEASUREMENTS The significant endocytoscopic features in differentiating among types of serrated polyps. RESULTS Of the 58 eligible lesions, 27 were classified as HP, 12 as SSA/P, and 19 as TSA. Most HPs (77.8%) had star-like lumens, and most SSA/Ps (83.3%) had oval lumens. The lumens of TSAs were serrated (31.6%) or villous (68.4%), with both shapes seen only in TSAs. Most HPs (92.6%) and SSA/Ps (75.0%) had small, round nuclei, and all TSAs had fusiform nuclei. Features significantly differentiating TSAs from HPs and SSA/Ps were the presence of fusiform nuclei (P < .001) and villous (P < .001) and serrated (P = .002) lumens. The presence of oval lumens was significantly characteristic of SSA/Ps (P < .001), and the presence of star-like lumens was significantly characteristic of HPs (P < .001). LIMITATIONS Retrospective design. Single-center study. CONCLUSION The shape of lumens and nuclei on endocytoscopy can efficiently differentiate among the different types of serrated polyps. ( CLINICAL TRIAL REGISTRATION NUMBER UMIN Clinical Trials Registry UMIN000007850.).

Vascular pattern classification of colorectal lesions with narrow band imaging magnifying endoscopy.

Magnifying narrow band imaging (NBI) has enabled to observe the vascular pattern of colorectal lesions. Their broad findings have been divided into six groups according to endoscopical vascular features: normal, faint, network, dense, irregular and sparse. Most hyperplastic polyps show a faint pattern. The vascular patterns of adenomas are mainly network or dense ones. The predominant vascular patterns of cancer were irregular and sparse. Indeed, irregular pattern has found to be characteristic for protruded or flat‐elevated cancer, whereas sparse pattern unique for depressed cancer. Through NBI, neoplastic lesions could be differentiated from those non‐neoplastic with sensitivity of 83.5%, specificity of 98.7% and accuracy of 98.2%. It was able to distinguish between massively submucosal invasive cancers and slightly submucosal invasive cancers by using the vascular pattern with 91.0% sensitivity and 79.4% specificity. The overall accuracy was 88.3%. NBI system has showed to be a valuable technique for distinguishing neoplastic from non‐neoplastic lesions, as well as massively from slightly submucosal invasive cancer. Therefore, vascular pattern analysis might be a promising tool for determining treatment selection, whether endoscopical or surgically.

Endoscopic characteristics of colorectal serrated lesions.

BACKGROUND/AIMS With the recent changes of pathological concepts, colorectal serrated lesions can be now divided into traditional serrated adenoma, typical hyperplastic polyp and sessile serrated polyp. The aim of this study is to clarify the endoscopic differences among these three groups. METHODOLOGY A total number of 362 serrated lesions larger than 5mm were evaluated. These were detected with ordinary view and observed also with magnifying chromoendoscopic view. The final pathologic diagnosis of the resected specimens was made blinded. RESULTS There were significant differences between traditional serrated adenoma and sessile serrated polypconcerning location, configuration and color. In chromoendoscopy, most of sessile serrated polyps and typical hyperplastic polyps showed star-like pattern, in contrast with traditional serrated adenomas most of which had fernor pinecone-like pattern. The differential diagnosis between traditional sessile polyp and the other two was possible with high accuracy. On the other hand, endoscopic distinction between sessile serrated polyp and typical hyperplastic polyp was not easy, except that the location and size were significantly different. CONCLUSIONS We can endoscopically differentiate between traditional serrated adenoma and sessile serrated polyp or typical hyperplastic polyp, but it is difficult to differentiate between the latter two.

Endocytoscopy can provide additional diagnostic ability to magnifying chromoendoscopy for colorectal neoplasms

Pit pattern (PIT) diagnosis with magnifying chromoendoscopy is effective diagnostic method for predicting a massively invasive submucosal colorectal cancer (SMm) which has possibility of metastasis, whereas endocytoscopy (EC) is recently reported to provide excellent diagnostic ability by enabling in vivo cellular visualization. The aim was to assess the additional diagnostic value of EC to PIT for diagnosing colorectal lesions.

Double staining with crystal violet and methylene blue is appropriate for colonic endocytoscopy: An in vivo prospective pilot study

Endocytoscopy (EC) at ultra‐high magnification enables in vivo visualization of cellular atypia of gastrointestinal mucosae. Clear images are essential for precise diagnosis by EC. The aim of the present study was to evaluate the optimal staining method for EC in the colon.

Use of endocytoscopy for identification of sessile serrated adenoma/polyps and hyperplastic polyps by quantitative image analysis of the luminal areas

Background and study aims  Recent studies that used magnifying chromoendoscopy and endocytoscopy (EC) to investigate endoscopic features of sessile serrated adenoma/polyps (SSA/Ps) suggested that a dilated crypt opening was an important indicator of SSA/Ps. However, no studies to date have measured the actual extent of dilatation. Hence, we investigated retrospectively the luminal areas using EC to determine a cutoff value for differentiating SSA/Ps from hyperplastic polyps (HPs). Patients and methods  A total of 101 lesions, including 25 SSA/Ps, 66 HPs, and 10 normal mucosal samples, assessed by an integrated-type EC were collected. For each lesion, 1 image that showed the widest lumen was selected and the average area of the contiguous 3 lumens were calculated. The cutoff value differentiating SSAPs from HPs was determined by receiver operating curve (ROC) analysis. Results  The mean luminal areas of SSA/Ps and HPs were 4152 μm 2 and 2117 μm 2 , respectively. ROC analysis found that a luminal area cutoff of 3068 μm 2 had a sensitivity of 80.0 %, a specificity of 77.3 %, an accuracy of 78.0 %, and an area under the ROC curve of 0.865. Furthermore, a cutoff of ≥ 556 μm 2 was found to accurately distinguish between HPs and normal mucosa (sensitivity 98.5 %, specificity 100 %, accuracy 98.7 %, and AUC 0.998). Conclusions  EC analysis of the luminal area is useful for differentiating between SSAPs and HPs. This approach could be adapted for computer-aided diagnosis of SSA/P.