[Intestinal malrotation accompanied by a right paraduodenal hernia in an adult: a case report].

A 72-year-old woman was admitted to our department in March 2020 for an evaluation of nausea, vomiting, diarrhea, liver dysfunction, and hypokalemia, which had persisted intermittently since 2013. Thickening of the descending duodenal wall and a sac-like appearance the intestinal tract in the vicinity of the duodenal papilla were observed in abdominal computed tomography. No duodenojejunal curvature, with two intestinal loops identified in the descending region, was detected in contrast-enhanced upper gastrointestinal imaging. Based on these imaging findings, the patient was diagnosed with intestinal malrotation (incomplete rotation and fixation) accompanied by a right paraduodenal hernia based on the Nishijima classification. Thus, surgery was performed at our hospital. Gastrointestinal symptoms did not recur, and liver dysfunction and hypokalemia improved postoperatively.

Efficacy of screening using annual fecal immunochemical test alone versus combined with one-time colonoscopy in reducing colorectal cancer mortality: the Akita Japan population-based colonoscopy screening trial (Akita pop-colon trial).

PURPOSE: Screening programs using fecal occult blood testing help reduce mortality from colorectal cancer (CRC). Colonoscopy and colonoscopy combined with fecal occult blood testing are considered alternatives with higher sensitivity than fecal tests; however, to our knowledge, randomized controlled trials (RCTs) providing such evidence have not been reported. Therefore, this study aimed to compare screening using the fecal immunochemical test (FIT) combined with colonoscopy and FIT alone to evaluate the efficacy of colonoscopy screening in reducing CRC mortality. METHODS: This multicenter, prospective, randomized, controlled study included average-risk individuals for CRC living in the study areas and aged 40-74 years. The exclusion criteria were history of CRC, hereditary non-polyposis CRC, familial adenomatous polyposis, inflammatory bowel diseases, history of cancer other than CRC within the past 5 years, and not expected to survive from comorbid illness. The intervention group underwent one-time colonoscopy and annual FIT, while the control group underwent annual FIT. The primary endpoint was mortality from CRC, while the secondary endpoints were cumulative incidence of invasive CRC, advanced CRC (invasion into the muscle layer or deeper), invasive cancer and screening sensitivities and specificities of invasive CRC, whole CRC, advanced neoplasia, and prevalence of adverse events. The intervention and control groups comprised 4876 and 4875 participants, respectively. CONCLUSION: This explanatory RCT evaluated the efficacy of colonoscopy screening by valid statistical inference based on randomization. Data on adverse events from this kind of screening are necessary when considering implementation of future screening programs. TRIAL REGISTRATION: UMIN Clinical Trials Registry, number UMIN000001980.

The concept of 'Semi-clean colon' using the pit pattern classification system has the potential to be acceptable in combination with a <3-year surveillance colonoscopy.

Histological features of colorectal lesions are currently evaluated via a magnifying chromoendoscopy [pit pattern (PIT) classification]. Advanced histological features are rarely observed in diminutive (≤5 mm) adenomatous polyps (DAPs). The Japanese guidelines indicate that diminutive neoplastic lesions without carcinomatous findings may be left untreated and followed up. At the present institution, DAPs with type IIIL PIT are left untreated in various cases, whereas lesions with type III, IV or V PIT are typically resected via routine colonoscopy. This retrospective study aimed to assess the management of DAPs using PIT classification. The participants of the study included patients <30 years previously referred for an initial colonoscopy, then reobserved for <3 years following the procedure. Participants were classified into three groups: Group A, Patients with type IIIL PIT DAP left untreated (semi-clean colon group); group B, patients with all neoplastic polyps, including DAPs, resected (clean colon group); and group C, patients without any adenomatous polyps (internal control group). The cumulative incidence of the index lesions (ILs) at the follow-up colonoscopy was analysed among the three groups. A total of 4,313 patients were enrolled in the study, with categorization as follows: Group A, 1,246; group B, 1,205; and group C, 1,862 patients. ILs were detected in group A, 100 (8.0%); group B, 104 (8.6%); and group C, 29 (1.6%) patients. There was no significant difference observed between groups A and B. It was verified that removing the type IIIL PIT DAPs did not decrease the incidence of ILs within a 3-year time period. Therefore, these polyps may be left untreated in combination with patient reobservation at an appropriate time interval, potentially one equal to that suggested following a polypectomy.

'Head Invasion' Is Not a Metastasis-Free Condition in Pedunculated T1 Colorectal Carcinomas Based on the Precise Histopathological Assessment.

BACKGROUND/AIM: Previous reports stated that pedunculated T1 colorectal carcinomas with 'head invasion' showed almost no nodal metastasis, requiring endoscopic treatment alone. However, clinically, some lesions develop nodal metastasis. We aimed to validate the necessity of distinguishing between 'pedunculated' and 'non-pedunculated' lesions, and also between 'head' and 'stalk' invasions. METHODS: Initial or additional surgery with lymph node dissection was performed in 76 pedunculated and 594 non-pedunculated cases. Among pedunculated lesions, the baseline was defined as the junction line between normal and neoplastic epithelium (Haggitt's level 2). The degree of invasion was classified as 'head invasion' (above the baseline) or 'stalk invasion' (beyond the baseline). Clinicopathological factors were analyzed with respect to nodal metastasis. RESULTS: Nine of 76 (11.8%) pedunculated cases and 52/594 (8.8%) non-pedunculated cases developed nodal metastasis (p = 0.40). No significant differences were found in the rate of nodal metastasis between 'head invasion' (4/30, 13.3%) and 'stalk invasion' (5/46, 10.9%). All the 4 cases with 'head invasion' had at least one pathological factor. CONCLUSIONS: 'Head invasion' was not a metastasis-free condition. Even for pedunculated T1 cancers with 'head invasion', additional surgery with lymph node dissection should be considered if these have pathological risk factors.

Comparison of the endocytoscopic and clinicopathologic features of colorectal neoplasms.

BACKGROUND AND AIM: Permeation of a vein or lymphatic vessel by a tumor is a key risk factor for lymph node metastasis. We examined the features of colorectal tumor vessel permeation using endocytoscopy, an ultra-high magnifying endoscopic system combined with a narrow-band imaging capability (EC-NBI). PATIENTS AND METHODS: We examined 188 colorectal lesions using EC-NBI before treatment was started. We measured the diameters of tumor vessels on EC-NBI images. We used the tumor vessel diameter (the mean diameter of four tumor-associated vessels) and the variation in tumor vessel caliber (the difference between the maximum and minimum diameters of the vessels expressed as a proportion) to judge changes in vessel formation. We examined the relationship between these variables and the extent of venous or lymphatic vessel permeation (vessel invasion) established by immunohistochemical examination of the resected specimen using monoclonal antibodies against the CD34 and D2 - 40 antigens. We also analyzed the relationships between tumor vessel diameter, tumor vessel caliber variation, and depth of tumor invasion. RESULTS: There were significant differences in tumor vessel diameter and caliber variation between tumors in situ and T1 - T3 carcinomas. In T1 carcinomas, larger tumor vessel diameter and greater tumor vessel caliber variation were significantly associated with venous permeation. In T2 and T3 carcinomas, greater tumor vessel caliber variation was significantly associated with venous permeation. CONCLUSIONS: The vessel diameter and caliber variation of colorectal tumor microvasculature are associated with depth of invasion and venous permeation, especially in T1 carcinomas.

Practical problems of measuring depth of submucosal invasion in T1 colorectal carcinomas.

PURPOSE: Submucosal invasion depth (SID) in colorectal carcinoma (CRC) is an important factor in estimating risk of lymph node metastasis, but can be difficult to measure, leading to inadequate or over-extensive treatment. Here, we aimed to clarify the practical aspects of measuring SID in T1 CRC. METHODS: We investigated 568 T1 CRCs that were resected surgically at our hospital from April 2001 to December 2013, and relationships between SID and clinicopathological factors, including the means of measurement, lesion morphology, and lymph node metastasis. RESULTS: Of these 568 lesions, the SID was ≥1000 µm in 508 lesions. SIDs for lesions measured from the surface layer were all ≥1000 µm. Although lesions with SIDs ≥1000 µm were associated with significantly higher levels of unfavorable histologic types and lymphovascular infiltration than shallower lesions, a depth of ≥1000 µm was not a significant risk factor for lymph node metastasis (LNM) (6.7 vs. 9.8 %; P = 0.64), and no lesions for which the sole pathological factor was SID ≥1000 µm had lymph node metastasis. Protruded lesions showed deeper SIDs than other types. CONCLUSIONS: Although we found several problems of measuring SID in this study, we also found, surprisingly, that SID is not a risk factor for lymph node metastasis, and its measurement is not needed to estimate the risk of lymph node metastasis.

Management of T1 colorectal cancers after endoscopic treatment based on the risk stratification of lymph node metastasis.

BACKGROUND AND AIM: Recent advances in endoscopic technology have allowed many T1 colorectal carcinomas to be resected endoscopically with negative margins. However, the criteria for curative endoscopic resection remain unclear. We aimed to identify risk factors for nodal metastasis in T1 carcinoma patients and hence establish the indication for additional surgery with lymph node dissection. METHODS: Initial or additional surgery with nodal dissection was performed in 653 T1 carcinoma cases. Clinicopathological factors were retrospectively analyzed with respect to nodal metastasis. The status of the muscularis mucosae (MM grade) was defined as grade 1 (maintenance) or grade 2 (fragmentation or disappearance). The lesions were then stratified based on the risk of nodal metastasis. RESULTS: Muscularis mucosae grade was associated with nodal metastasis (P = 0.026), and no patients with MM grade 1 lesions had nodal metastasis. Significant risk factors for nodal metastasis in patients with MM grade 2 lesions were attribution of women (P = 0.006), lymphovascular infiltration (P < 0.001), tumor budding (P = 0.045), and poorly differentiated adenocarcinoma or mucinous carcinoma (P = 0.007). Nodal metastasis occurred in 1.06% of lesions without any of these pathological factors, but in 10.3% and 20.1% of lesions with at least one factor in male and female patients, respectively. There was good inter-observer agreement for MM grade evaluation, with a kappa value of 0.67. CONCLUSIONS: Stratification using MM grade, pathological factors, and patient sex provided more appropriate indication for additional surgery with lymph node dissection after endoscopic treatment for T1 colorectal carcinomas.

Characteristics of colorectal tumours in asymptomatic patients with negative immunochemical faecal occult blood test results.

The immunochemical faecal occult blood test (iFOBT) is a simple, non-invasive colorectal cancer (CRC) screening method for reducing CRC-related mortality. However, the sensitivity of iFOBT is imperfect and certain colonic neoplasms that require removal may be missed. The aim of this study was to investigate the incidence and characteristics of CRC in asymptomatic, iFOBT-negative patients who underwent opportunistic screening. A total of 919 subclinical patients (276 iFOBT-positive and 643 iFOBT-negative) in the health screening program of our hospital underwent total colonoscopy (TCS) within 2 years after iFOBT. The patients were divided into an iFOBT-positive and an iFOBT-negative group and the TCS findings were compared between the two groups. Although the incidence of advanced neoplasia (CRC, high-grade dysplasia, adenoma sized ≥10 mm and tubulovillous adenoma) was significantly higher in the iFOBT-positive group, these lesions were also found in 6.3% of iFOBT-negative patients. The lesions tended to be proximally located and non-protruding. In conclusion, screening with iFOBT remains clinically significant. However, colonoscopy is indispensable for reducing the incidence and mortality of CRC.

[Whipple's disease].

A 36-year-old woman presented with fever, diarrhea, and weight loss in April 2011. Upper GI endoscopy and colonoscopy showed a diffuse yellow-white shaggy mucosa in the second part of the duodenum and the ileum end, respectively. These lesions in these 2 locations were biopsied, and both specimens showed distended epithelial villi and massive infiltration of foamy macrophages in the lamina propria. PCR was performed to identify causative bacilli. DNA extracted from the duodenal mucosa showed a specific PCR product, confirming the diagnosis of Whipple's disease. The patient was treated with a 2-week course of ceftriaxone, followed by sulfamethoxazole/trimethoprim. After we started the treatment, the patient developed complications of infective endocarditis and meningitis. The patient was relieved of her symptoms using a combination of gentamicin, penicillin G, ampicillin, meropenem, and vancomycin.

Depressed-Type Colonic Lesions and "De Novo" Cancer in Familial Adenomatous Polyposis: A Colonoscopist's Viewpoint.

Familial adenomatous polyposis (FAP) is the most common inherited polyposis syndrome. Almost all patients with FAP will develop colorectal cancer if their FAP is not identified and treated at an early stage. Although there are many reports about polypoid lesions and colorectal cancers in FAP patients, little information is available concerning depressed lesions in FAP patients. Several reports suggested that depressed-type lesions are characteristic of FAP and important in the light of their rapid growth and high malignancy. Here, we describe the occurrence of depressed-type lesions in FAP patients treated at our institution. Between April 2001 and March 2010, eight of 18 FAP patients had colorectal cancers. Depressed-type colorectal cancer was found in three patients. It should be kept in mind that depressed-type lesions occur even in FAP.

[NBI magnifying endoscopic classification using crystal violet staining].

NBI magnifying imaging with crystal violet (CV-NBI magnifying imaging) makes recognition of micro-vascular pattern and grandular structure in the gastric mucosa better. NBI image emphasizes micro-vascular structure in mucosal surface. Magnification endoscopy with crystal violet staining delineates surface grandular structure better than without it. Crystal violet stained epithelium is clearly observed as cobalt green with NBI imaging. In the classification of CV-NBI magnification findings, 71% of differentiated type lesion was classified into ILL (intralobular loop pattern), and the rest (29%) was diagnosed as FNP (fine network pattern) which was originally advocated by Nakayoshi, et al. ILL is the new category of magnifying endoscopy. ILL corresponded mainly to differentiated-type adenocarcinoma, but it also includes undifferentiated-type adenocarcinoma. Corkscrew pattern is corresponding well to undifferentiated-type adnocarcinoma (Nakayoshi, et al). CV-NBI magnifying classification is considered to be related to tissue characterization in gastric cancer.