Hiroshi Kawano

Narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

Many clinical studies on narrow‐band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low‐grade intramucosal neoplasia, high‐grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.

NBI magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team (JNET)

Many clinical studies on narrow‐band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low‐grade intramucosal neoplasia, high‐grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.

Current status and future perspectives of endoscopic diagnosis and treatment of diminutive colorectal polyps

During colonoscopy, small and diminutive colorectal polyps are commonly encountered. It is estimated that at least one adenomatous polyp is detected in almost half of all patients undergoing screening colonoscopy. In contrast, the ‘predict, resect, and discard’ strategy for diminutive and small colorectal polyps is a current topic especially in Western countries. ‘Is this an acceptable policy in Japan?’ Herein, we report the results of a questionnaire survey with regard to the management of diminutive colorectal polyps, including the thoughts of Japanese endoscopists regarding the ‘predict, resect, and discard’ strategy. At the moment, we propose that this strategy should be used by skilled endoscopists only.

Improved visibility of colorectal flat tumors using image-enhanced endoscopy.

Colonoscopy is considered the gold standard for detecting colorectal tumors; however, conventional colonoscopy can miss flat tumors. We aimed to determine whether visualization of colorectal flat lesions was improved by autofluorescence imaging and narrow‐band imaging image analysis in conjunction with a new endoscopy system. Eight physicians compared autofluorescent, narrow‐band, and chromoendoscopy images to 30 corresponding white‐light images of flat tumors. Physicians rated tumor visibility from each image set as follows: +2 (improved), +1 (somewhat improved), 0 (equivalent to white light), −1 (somewhat decreased), and −2 (decreased). The eight scores for each image were totalled and evaluated. Interobserver agreement was also examined. Autofluorescent, narrow‐band, and chromoendoscopy images showed improvements of 63.3% (19/30), 6.7% (2/30), and 73.3% (22/30), respectively, with no instances of decreased visibility. Autofluorescence scores were generally greater than narrow‐band scores. Interobserver agreement was 0.65 for autofluorescence, 0.80 for narrow‐band imaging, and 0.70 for chromoendoscopy. In conclusion, using a new endoscopy system in conjunction with autofluorescent imaging improved visibility of colorectal flat tumors, equivalent to the visibility achieved using chromoendoscopy.

Adult pancreatic hemangioma: A case report

Vascular neoplasms of the pancreas are extremely rare and usually manifest as symptomatic, cystic lesions. This study presents a case that includes the clinicopathologic information used to discriminate pancreatic hemangioma from other types of cystic lesion of the pancreas. A 40-year-old female visited hospital with a chief complaint of abdominal pain. The serum CEA and CA19-9 levels of the patient were within the normal limits. An abdominal computed tomography scan and magnetic resonance imaging showed a 100-mm mass lesion in the body and tail of the pancreas, and the tumor extended toward the retroperitoneum and surrounded the splenic vein. The lesion was subsequently resected. Macroscopically, it was a multiloculated cyst with intracystic hemorrhage. Microscopically, the lesion was composed of numerous, heterogeneous cysts lined by a flattened single layer of cells without significant atypia. Notably, numerous neoplastic vessels extended into the interlobular septa of the pancreas and surrounded the main pancreatic duct. Immunohistochemical analysis showed that the lining cells expressed CD31 and CD34. The lesion was diagnosed as adult pancreatic hemangioma. Surgical treatment may be required when a direct contact between the lesion and the pancreatic tissue is demonstrated using imaging.

Screening colonoscopy in Australia

Colorectal cancer (CRC) is a global epidemic predominantly affecting Western countries. It is the second leading cause of cancer‐related deaths in Australia with one in 12 Australians affected by this condition by the age of 85 years. Appropriate preventive measures by screening followed by colonoscopy can detect cancer and precancerous lesions, which are potentially curable. The National Bowel Cancer Screening Program (NBCSP) is a national screening program implemented by the Australian Government aimed at reducing morbidity and mortality from bowel cancer by actively recruiting and screening the target population. The long‐term goal of the program is to include the at‐risk population (50–74 years of age) in a biennial screening program. Newer technologies could have a potential role in screening programs by enhancing adenoma detection rates. However, until more evidence is available, improving screening uptake and bowel preparation strategies are the prime focus in reducing CRC‐related morbidity and mortality.

Screening colonoscopy: What is the most reliable modality for the detection and characterization of colorectal lesions?

Colonoscopy is considered the best modality for the detection and treatment of colorectal polyps. However, some polyps still may not be detected. Although conventional white‐light endoscopy is the gold standard for the detection of colorectal polyps, up to a fifth of lesions may be missed on screening colonoscopy, especially non‐polypoid colorectal neoplasms. Recently, many studies have reported on various endoscopic modalities that improve the detection and characterization of colorectal lesions. Newly developed modalities might be helpful to recognize colorectal lesions; however, careful observation is required to identify flat/depressed lesions as well as hidden polyps during screening and surveillance colonoscopy.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (Translated Version)

Hereditary colorectal cancer accounts for less than 5% of all colorectal cancer cases. Some of the unique characteristics that are commonly encountered in cases of hereditary colorectal cancer include early age at onset, synchronous/metachronous occurrence of the cancer, and association with multiple cancers in other organs, necessitating different management from sporadic colorectal cancer. While the diagnosis of familial adenomatous polyposis might be easy because usually 100 or more adenomas that develop in the colonic mucosa are in this condition, Lynch syndrome, which is the most commonly associated disease with hereditary colorectal cancer, is often missed in daily medical practice because of its relatively poorly defined clinical characteristics. In addition, the disease concept and diagnostic criteria for Lynch syndrome, which was once called hereditary non‐polyposis colorectal cancer, have changed over time with continual research, thereby possibly creating confusion in clinical practice. Under these circumstances, the JSCCR Guideline Committee has developed the “JSCCR Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (HCRC), to allow delivery of appropriate medical care in daily practice to patients with familial adenomatous polyposis, Lynch syndrome, or other related diseases. The JSCCR Guidelines 2016 for HCRC were prepared by consensus reached among members of the JSCCR Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR Guidelines 2016 for HCRC.

Validation study for development of the Japan NBI Expert Team (JNET) classification of colorectal lesions.

The Japan narrow‐band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions.

Endoscopic analysis of colorectal serrated lesions with cancer

Serrated lesions, including hyperplastic polyps (HPs), traditional serrated adenomas (TSAs) and sessile serrated adenomas/polyps (SSA/Ps), are important contributors to colorectal carcinogenesis. The aim of the present study was to analyze the potential of conventional endoscopy and advanced endoscopic imaging techniques to delineate the characteristic features of serrated lesions with cancer. The present study was a retrospective analysis of the data of 168 patients who had undergone colonoscopy, and a total of 228 serrated lesions (77 HPs, 58 TSAs, 84 SSA/Ps, 9 SSA/P plus TSAs) have been identified in these patients. A cancer component was identified in 2.6% of HPs, 13.8% of TSAs and 10.7% of SSA/Ps, but none of SSA/P plus TSAs. Compared with the lesions without cancer, the lesions with cancer exhibited a larger size (HP, TSA and SSA/P), a reddish appearance (SSA/P), a two-tier raised appearance (HP and SSA/P), a central depression (HP, TSA and SSA/P), the type V pit pattern (HP, TSA and SSA/P), and/or the type III capillary pattern (TSA and SSA/P). Deep invasion was identified in 50.0% of HPs, 12.5% of TSAs and 55.6% of SSA/Ps with cancer. The Ki-67 proliferative zone was distributed diffusely within the area of the cancer, but partially within the non-cancer area of HPs, TSAs and SSA/Ps. The lesion types were also analyzed on the basis of mucin phenotype. The present study suggested that a detailed endoscopic analysis of serrated lesions with cancer is useful for delineating characteristic features, and the analysis aids treatment selection.