Prospective real-time evaluation of diagnostic performance using endocytoscopy in differentiating neoplasia from nonneoplasia for colorectal diminutive polyps(≤ 5 mm)

AIM To clarify the diagnostic performance of endocytoscopy for differentiation between neoplastic and nonneoplastic colorectal diminutive polyps.METHODS Patients who underwent endocytoscopy between October and December 2016 at Sano Hospital were prospectively recruited. When diminutive polyps(≤5 mm) were detected, the lesions were evaluated by endocytoscopy after being stained with 0.05% crystal violet and 1% methylene blue. The diminutivepolyps were classified into five categories(EC 1 a, 1 b, 2, 3 a, and 3 b). Endoscopists were asked to take a biopsy from any lesion diagnosed as EC1 b(indicator of hyperplastic polyp) or EC2(indicator of adenoma). We have assessed the diagnostic performance of endocytoscopy for EC2 and EC1 b lesions by comparison with the histopathology of the biopsy specimen. RESULTS A total of 39 patients with 63 diminutive polyps were analyzed. All polyps were evaluated by endocytoscopy. The mean polyp size was 3.3 ± 0.9 mm. Among the 63 diminutive polyps, 60 were flat and 3 were pedunculated. The mean time required for EC observation, including the time for staining with crystal violet and methylene blue, was 3.0 ± 1.9 min. Histopathologic evaluation showed that 13 polyps were hyperplastic and 50 were adenomas. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of EC2 for adenoma compared with EC1 b for hyperplastic polyp were 98.0%, 92.3%, 96.8%, 98.0% and 92.3%, respectively. There were only two cases of disagreement between the endoscopic diagnosis made by endocytoscopy and the corresponding histopathological diagnosis.CONCLUSION Endocytoscopy showed a high diagnostic performance for differentiating between neoplastic and non-neoplastic colorectal diminutive polyps, and therefore has the potential to be used for "real-time histopathology".

Successful endoscopic procedures for intraductal papillary neoplasm of the bile duct:A case report

Attention has recently been focused on biliary papillary tumors as the novel disease entity intraductal papillary neoplasm of the bile duct(IPNB),which consists of papillary proliferation of dysplastic biliary epithelium.As even benign papillary tumors are considered as premalignant,some investigators recommend aggressive surgical therapy for IPNB,although no guidelines are available to manage this disease.Few reports have described long-term follow-up of patients with benign IPNB without radical resection.If patients with IPNB who are treated only with endoscopic procedures are noted,clinical profiles and alternative therapies other than resection may be recommended.We report the case of a patient who experienced repetitive cholangitis for 10 years and was finally diagnosed with IPNB.Radical resection could not be recommended because of the age of the patient,therefore,endoscopic sphincterotomy was performed.Although an endoscopic retrograde biliary drainage catheter was placed several times for repetitive cholangitis,the patient has done well during follow-up.Our case may offer insights into the natural course and management decisions for the novel disease entity of IPNB.

New application of endocytoscope for histopathological diagnosis of colorectal lesions

BACKGROUND The endocytoscope with ultra-high magnification(x 520)allows us to observe the cellular structure of the colon epithelium during colonoscopy,known as virtual histopathology.We hypothesized that the endocytoscope could directly observe colorectal histopathological specimens and store them as endocyto-pathological images by the endoscopists without a microscope,potentially saving the burden on histopathologists.AIM To assess the feasibility of endocyto-pathological images taken by an endoscopist as adequate materials for histopathological diagnosis.METHODS Three gastrointestinal pathologists were invited and asked to diagnose 40 cases of endocyto-pathological images of colorectal specimens.Each case contained seven endocyto-pathological images taken by an endoscopist,consisting of one loupe image,three low-magnification images,and three ultra-high magnification images.The participants chose hyperplastic polyp or low-grade adenoma for 20 cases of endocyto-pathological images(10 hyperplastic polyps,and 10 Low-grade adenomas in conventional histopathology)in study 1 and high-grade adenoma/shallow invasive cancer or deep invasive cancer for 20 cases[10 tumor in situ/T1a and 10 T1b]in study 2.We investigated the agreement between the histopathological diagnosis using the endocyto-pathological images and conventional histopathological diagnosis.RESULTS Agreement between the endocyto-pathological and conventional histopathological diagnosis by the three gastrointestinal pathologists was 100%(95%CI:94.0%–100%)in studies 1 and 2.The interobserver agreement among the three gastrointestinal pathologists was 100%,and theκcoefficient was 1.00 in both studies.CONCLUSION Endocyto-pathological images were adequate and reliable materials for histopathological diagnosis.