Spontaneous Resolution of Strangulated Small Bowel Obstruction in a Patient With Intestinal Tuberculosis After Starting Anti-tuberculosis Drugs: A Case Report.

Intestinal tuberculosis can cause strangulated small bowel obstruction. Strangulated small bowel obstruction usually requires surgery. We report a case of a patient with intestinal tuberculosis, who developed a spontaneously resolving strangulated small bowel obstruction after the commencement of anti-tuberculosis drugs. A 72-year-old woman presented with abdominal pain and ascites was noticed on abdominal ultrasonography. Contrast-enhanced computed tomography (CT) revealed a 50-mm tumor in the ileocecal region that was darkly contrasted, along with peritoneal thickening and ascites. A malignant tumor and carcinomatous peritonitis were suspected. Colonoscopy showed an ulcerative lesion in the terminal ileum, and the acid-fast bacillus culture was positive; therefore, the patient was diagnosed with intestinal tuberculosis and was treated with isoniazid, rifampicin, ethambutol, and pyrazinamide. After commencing treatment, improvement in peritoneal thickening and ascites was confirmed using abdominal ultrasonography; therefore, we concluded that the ascites was due to tuberculous peritonitis. Six weeks after the initiation of treatment, the patient visited our facility with complaints of abdominal pain. Contrast-enhanced CT revealed unenhanced small intestinal walls, and a diagnosis of strangulated small bowel obstruction was made; however, her symptoms improved naturally. Strangulated small bowel obstruction was presumed to be due to the presence of bands as anti-tuberculosis therapy could promote fibrosis. In this case, abdominal ultrasonography was useful in the evaluation of the effects of treatment.

Sessile serrated adenoma/polyp showed rapid malignant transformation in the final 13 months.

Based on the concept of the adenoma-carcinoma sequence, most colorectal cancers are considered to arise from conventional adenomas. However, recent studies suggested that a subset of colorectal cancers develop through the serrated neoplastic pathway. It has also been documented that serrated polyps can rapidly transform into invasive cancers even when they are small in size. We now describe a case of a sessile serrated adenoma/polyp which had been followed up for 4 years but eventually showed rapid transformation into an advanced cancer accompanied by a remarkable morphological change within only 13 months. Retrospective genetic and epigenetic analyses showed microsatellite instability, CpG island methylator phenotype-positive, and BRAF mutation in the lesion, suggesting the tumor had developed through the serrated neoplastic pathway. This case may provide valuable information about the natural history of sessile serrated adenoma/polyps which eventually progress to advanced cancers.

Surface microstructures are associated with mutational intratumoral heterogeneity in colorectal tumors.

BACKGROUND: Recent studies revealed that colorectal tumors are composed of genetically diverse subclones. We aimed to clarify whether the surface microstructures of colorectal tumors are associated with genetic intratumoral heterogeneity (ITH). METHODS: The surface microstructures (pit patterns) of colorectal tumors were observed using magnifying endoscopy, and biopsy specimens were obtained from respective areas when tumors exhibited multiple pit patterns. A total of 711 specimens from 477 colorectal tumors were analyzed for BRAF, KRAS and TP53 mutations using pyrosequencing and direct sequencing. A panel of cancer-related genes was analyzed through targeted sequencing in 7 tumors. RESULTS: Colorectal tumors with multiple pit patterns exhibited more advanced pit patterns and higher frequencies of KRAS and/or TP53 mutations than tumors with a single pit pattern. In tumors with multiple pit patterns, mutations were observed as public (common to all areas) or private (specific to certain areas), and private KRAS and/or TP53 mutations were often variable and unrelated to the pit pattern grade. Notably, invasive CRCs frequently exhibited public TP53 mutations, even in adenomatous areas, which is indicative of their early malignant potential. Targeted sequencing revealed additional public and private mutations in tumors with multiple pit patterns, indicating their single clonal origin. CONCLUSIONS: Our results suggest intratumoral pit pattern variation does not simply reflect the process of colorectal tumor evolution, but instead represents genetically diverse subclones, and this diversity may be associated with malignant potential.

Subtypes of the Type II Pit Pattern Reflect Distinct Molecular Subclasses in the Serrated Neoplastic Pathway.

BACKGROUND: Colorectal serrated lesions (SLs) are important premalignant lesions whose clinical and biological features are not fully understood. AIMS: We aimed to establish accurate colonoscopic diagnosis and treatment of SLs through evaluation of associations among the morphological, pathological, and molecular characteristics of SLs. METHODS: A total of 388 premalignant and 18 malignant colorectal lesions were studied. Using magnifying colonoscopy, microsurface structures were assessed based on Kudo's pit pattern classification system, and the Type II pit pattern was subcategorized into classical Type II, Type II-Open (Type II-O) and Type II-Long (Type II-L). BRAF/KRAS mutations and DNA methylation of CpG island methylator phenotype (CIMP) markers (MINT1, - 2, - 12, - 31, p16, and MLH1) were analyzed through pyrosequencing. RESULTS: Type II-O was tightly associated with sessile serrated adenoma/polyps (SSA/Ps) with BRAF mutation and CIMP-high. Most lesions with simple Type II or Type II-L were hyperplastic polyps, while mixtures of Type II or Type II-L plus more advanced pit patterns (III/IV) were characteristic of traditional serrated adenomas (TSAs). Type II-positive TSAs frequently exhibited BRAF mutation and CIMP-low, while Type II-L-positive TSAs were tightly associated with KRAS mutation and CIMP-low. Analysis of lesions containing both premalignant and cancerous components suggested Type II-L-positive TSAs may develop into KRAS-mutated/CIMP-low/microsatellite stable cancers, while Type II-O-positive SSA/Ps develop into BRAF-mutated/CIMP-high/microsatellite unstable cancers. CONCLUSIONS: These results suggest that Type II subtypes reflect distinct molecular subclasses in the serrated neoplasia pathway and that they could be useful hallmarks for identifying SLs at high risk of developing into CRC.

Epigenetic silencing of SMOC1 in traditional serrated adenoma and colorectal cancer.

Colorectal sessile serrated adenoma/polyps (SSA/Ps) are well-known precursors of colorectal cancer (CRC) characterized by BRAF mutation and microsatellite instability. By contrast, the molecular characteristics of traditional serrated adenoma (TSAs) are not fully understood. We analyzed genome-wide DNA methylation in TSAs having both protruding and flat components. We identified 11 genes, including SMOC1, methylation of which progressively increased during the development of TSAs. SMOC1 was prevalently methylated in TSAs, but was rarely methylated in SSA/Ps (p < 0.001). RT-PCR and immunohistochemistry revealed that SMOC1 was expressed in normal colon and SSA/Ps, but its expression was decreased in TSAs. Ectopic expression of SMOC1 suppressed proliferation, colony formation and in vivo tumor formation by CRC cells. Analysis of colorectal lesions (n = 847) revealed that SMOC1 is frequently methylated in TSAs, high-grade adenomas and CRCs. Among these, SMOC1 methylation was strongly associated with KRAS mutation and CpG island methylator phenotype (CIMP)-low. These results demonstrate that epigenetic silencing of SMOC1 is associated with TSA development but is rarely observed in SSA/Ps. SMOC1 expression could thus be a diagnostic marker of serrated lesions, and SMOC1 methylation could play a role in neoplastic pathways in TSAs and conventional adenomas.

Endoscopic and molecular characterization of colorectal sessile serrated adenoma/polyps with cytologic dysplasia.

BACKGROUND AND AIMS: Sessile serrated adenoma/polyps (SSA/Ps), which are precursor lesions of colorectal cancer (CRC) with BRAF mutation and the CpG island methylator phenotype (CIMP), develop cytologic dysplasia (CD) during the progression of colorectal tumorigenesis. In the present study we aimed to clarify the endoscopic and molecular signatures of SSA/Ps, with and without CD. METHODS: A series of 208 serrated lesions, including 41 hyperplastic polyps, 90 SSA/Ps, 33 SSA/Ps with CD, and 44 traditional serrated adenomas, were observed and resected using magnifying endoscopy. BRAF and KRAS mutations and methylation of CIMP markers (MINT1, MINT2, MINT12, MINT31, and p16) were analyzed through pyrosequencing. Molecular alterations were then compared with endoscopic and pathologic characteristics. RESULTS: Among SSA/Ps without CD, the Type II-Open pit pattern (Type II-O), BRAF mutation, and CIMP were tightly associated with a proximal colon location. SSA/Ps in the distal colon infrequently exhibited Type II-O and CIMP. By contrast, most SSA/Ps with CD showed Type II-O plus adenomatous pit patterns (Type III or IV), BRAF mutation, and CIMP, irrespective of their locations. CONCLUSIONS: Our results suggest that the Type II-O plus III/IV pit pattern is a common feature of SSA/Ps with CD in both the proximal and distal colon and that this pit pattern is a hallmark of serrated lesions at high risk of developing into CRCs.

Randomised clinical study comparing the effectiveness and physiological effects of hypertonic and isotonic polyethylene glycol solutions for bowel cleansing.

OBJECTIVES: Bowel cleansing is necessary before colonoscopy, but is a burden to patients because of the long cleansing time and large dose volume. A low-volume (2 L) hypertonic polyethylene glycol-ascorbic acid solution (PEG-Asc) has been introduced, but its possible dehydration effects have not been quantitatively studied. We compared the efficacy and safety including the dehydration risk between hypertonic PEG-Asc and isotonic PEG regimens. DESIGN: This was an observer-blinded randomised study. Participants (n=310) were allocated to receive 1 of 3 regimens on the day of colonoscopy: PEG-Asc (1.5 L) and water (0.75 L) dosed with 1 split (PEG-Asc-S) or 4 splits (PEG-Asc-M), or PEG-electrolyte solution (PEG-ES; 2.25 L) dosed with no split. Dehydration was analysed by measuring haematocrit (Ht). RESULTS: The cleansing time using the hypertonic PEG-Asc-S (3.33±0.48 hours) was significantly longer than that with isotonic PEG-ES (3.05±0.56 hours; p<0.001). PEG-Asc-M (3.00±0.53 hours) did not have this same disadvantage. Successful cleansing was achieved in more than 94% of participants using each of the 3 regimens. The percentage changes in Ht from baseline (before dosing) to the end of dosing with PEG-Asc-S (3.53±3.32%) and PEG-Asc-M (4.11±3.07%) were significantly greater than that with PEG-ES (1.31±3.01%). CONCLUSIONS: These 3 lower volume regimens were efficacious and had no serious adverse effects. Even patients cleansed with isotonic PEG-ES showed significant physiological dehydration at the end of dosing. The four-split PEG-Asc-M regimen is recommended because of its shorter cleansing time without causing serious nausea. TRIAL REGISTRATION NUMBER: UMIN000013103; Results.

Assessment of epigenetic alterations in early colorectal lesions containing BRAF mutations.

To clarify the molecular and clinicopathological characteristics of colorectal serrated lesions, we assessed the DNA methylation of cancer-associated genes in a cohort of BRAF-mutant precancerous lesions from 94 individuals. We then compared those results with the lesions' clinicopathological features, especially colorectal subsites. The lesions included hyperplastic polyps (n = 16), traditional serrated adenomas (TSAs) (n = 15), TSAs with sessile serrated adenomas (SSAs) (n = 6), SSAs (n = 49) and SSAs with dysplasia (n = 16). The prevalence of lesions exhibiting the CpG island methylator phenotype (CIMP) was lower in the sigmoid colon and rectum than in other bowel subsites, including the cecum, ascending, transverse and descending colon. In addition, several cancer-associated genes showed higher methylation levels within lesions in the proximal to sigmoid colon than in the sigmoid colon and rectum. These results indicate that the methylation status of lesions with BRAF mutation is strongly associated with their location, histological findings and neoplastic pathways. By contrast, no difference in aberrant DNA methylation was observed in normal-appearing background colonic mucosa along the bowel subsites, which may indicate the absence of an epigenetic field defect.

Analysis of DNA methylation in bowel lavage fluid for detection of colorectal cancer.

Aberrant DNA methylation could potentially serve as a biomarker for colorectal neoplasms. In this study, we assessed the feasibility of using DNA methylation detected in bowel lavage fluid (BLF) for colorectal cancer screening. A total of 508 BLF specimens were collected from patients with colorectal cancer (n = 56), advanced adenoma (n = 53), minor polyp (n = 209), and healthy individuals (n = 190) undergoing colonoscopy. Methylation of 15 genes (miR-1-1, miR-9-1, miR-9-3, miR-34b/c, miR-124-1, miR-124-2, miR-124-3, miR-137, SFRP1, SFRP2, APC, DKK2, WIF1, LOC386758, and ZNF582) was then analyzed in MethyLight assays, after which receiver operating characteristic (ROC) curves were analyzed to assess the diagnostic performance of BLF methylation. Through analyzing BLF specimens in a training set (n = 345), we selected the three genes showing the greatest sensitivity for colorectal cancer detection (miR-124-3, 71.8%; LOC386758, 79.5%; and SFRP1, 74.4%). A scoring system based on the methylation of those three genes (M-score) achieved 82% sensitivity and 79% specificity, and the area under the ROC curve (AUC) was 0.834. The strong performance of this system was then validated in an independent test set (n = 153; AUC = 0.808). No significant correlation was found between M-score and the clinicopathologic features of the colorectal cancers. Our results demonstrate that DNA methylation in BLF specimens may be a useful biomarker for the detection of colorectal cancer.

Aberrant methylation of microRNA-34b/c is a predictive marker of metachronous gastric cancer risk.

BACKGROUND: Metachronous gastric cancer (GC) can develop after endoscopic resection of GC and cannot be predicted based on clinical signature. Aberrant DNA methylation in noncancerous gastric mucosa is strongly implicated in gastric carcinogenesis and could be a useful biomarker of GC risk. We evaluated the clinical utility of DNA methylation as a biomarker of metachronous GC risk. METHOD: We carried out scheduled follow-up endoscopy in 129 patients after curative endoscopic resection of GC. Biopsy specimens were collected from noncancerous mucosa in the gastric antrum and body, after which quantitative methylation analysis of miR-34b/c, SFRP1, SFRP2, SFRP5, DKK2 and DKK3 was carried out using bisulfite pyrosequencing. The utility of the methylation for predicting the risk of metachronous GC development was assessed using Kaplan-Meier and Cox proportional hazards model analyses. RESULTS: During the follow-up period, 17 patients (13%) developed metachronous GCs. The cumulative incidence of metachronous GC was significantly higher among patients with elevated miR-34b/c, SFRP2 and DKK2 methylation in their gastric body. MiR-34b/c showed the strongest association with the risk of metachronous GC, and the cumulative incidence of metachronous GC was much higher in the high-miR-34b/c-methylation group than the low-methylation group. Multivariate analysis adjusted for age, sex, H. pylori status and pathological findings showed miR-34b/c methylation in gastric body to be an independent predictor of metachronous GC risk. CONCLUSION: Our results suggest that methylation of miR-34b/c in the mucosa of the noncancerous gastric body may be a useful biomarker for predicting the risk of metachronous GC.

Aberrant methylation of RASGRF1 is associated with an epigenetic field defect and increased risk of gastric cancer.

Aberrant DNA methylation is implicated in the epigenetic field defect seen in gastric cancer. Our aim in this study was to identify predictive biomarkers by screening for DNA methylation in noncancerous background gastric mucosa from patients with gastric cancer. Using methylated-CpG island amplification coupled with CpG island microarray (MCAM) analysis, we identified 224 genes that were methylated in the noncancerous gastric mucosa of patients with gastric cancer. Among them, RASGRF1 methylation was significantly elevated in gastric mucosa from patients with either intestinal or diffuse type gastric cancer, as compared with mucosa from healthy individuals (8.3% vs. 22.4%, P < 0.001; 8.3% vs. 19.4%, P < 0.001). RASGRF1 methylation was independent of mucosal atrophy and could be used to distinguish both serum pepsinogen test-positive [sensitivity, 70.0%; specificity, 86.7%; area under the receiver operator characteristic (ROC) curve, AUC, 0.763] and -negative patients with gastric cancer (sensitivity, 72.2%; specificity, 87.0%; AUC, 0.844) from healthy individuals. Ectopic expression of RASGRF1 suppressed colony formation and Matrigel invasion by gastric cancer cells, suggesting it may be involved in gastric tumorigenesis. Collectively, our data suggest that RASGRF1 methylation is significantly involved in an epigenetic field defect in the stomach, and that it could be a useful biomarker to identify individuals at high risk for gastric cancer.

Molecular dissection of premalignant colorectal lesions reveals early onset of the CpG island methylator phenotype.

The concept of the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC) is widely accepted, although the timing of its occurrence and its interaction with other genetic defects are not fully understood. Our aim in this study was to unravel the molecular development of CIMP cancers by dissecting their genetic and epigenetic signatures in precancerous and malignant colorectal lesions. We characterized the methylation profile and BRAF/KRAS mutation status in 368 colorectal tissue samples, including precancerous and malignant lesions. In addition, genome-wide copy number aberrations, methylation profiles, and mutations of BRAF, KRAS, TP53, and PIK3CA pathway genes were examined in 84 colorectal lesions. Genome-wide methylation analysis of CpG islands and selected marker genes revealed that CRC precursor lesions are in three methylation subgroups: CIMP-high, CIMP-low, and CIMP-negative. Interestingly, a subset of CIMP-positive malignant lesions exhibited frequent copy number gains on chromosomes 7 and 19 and genetic defects in the AKT/PIK3CA pathway genes. Analysis of mixed lesions containing both precancerous and malignant components revealed that most aberrant methylation is acquired at the precursor stage, whereas copy number aberrations are acquired during the progression from precursor to malignant lesion. Our integrative genomic and epigenetic analysis suggests early onset of CIMP during CRC development and indicates a previously unknown CRC development pathway in which epigenetic instability associates with genomic alterations.

A novel pit pattern identifies the precursor of colorectal cancer derived from sessile serrated adenoma.

OBJECTIVES: Sessile serrated adenomas (SSAs) are known to be precursors of sporadic colorectal cancers (CRCs) with microsatellite instability (MSI), and to be tightly associated with BRAF mutation and the CpG island methylator phenotype (CIMP). Consequently, colonoscopic identification of SSAs has important implications for preventing CRCs, but accurate endoscopic diagnosis is often difficult. Our aim was to clarify which endoscopic findings are specific to SSAs. METHODS: The morphological, histological and molecular features of 261 specimens from 226 colorectal tumors were analyzed. Surface microstructures were analyzed using magnifying endoscopy. Mutation in BRAF and KRAS was examined by pyrosequencing. Methylation of p16, IGFBP7, MLH1 and MINT1, -2, -12 and -31 was analyzed using bisulfite pyrosequencing. RESULTS: Through retrospective analysis of a training set (n=145), we identified a novel surface microstructure, the Type II open-shape pit pattern (Type II-O), which was specific to SSAs with BRAF mutation and CIMP. Subsequent prospective analysis of an independent validation set (n=116) confirmed that the Type II-O pattern is highly predictive of SSAs (sensitivity, 65.5%; specificity, 97.3%). BRAF mutation and CIMP occurred with significant frequency in Type II-O-positive serrated lesions. Progression of SSAs to more advanced lesions was associated with further accumulation of aberrant DNA methylation and additional morphological changes, including the Type III, IV and V pit patterns. CONCLUSIONS: Our results suggest the Type II-O pit pattern is a useful hallmark of the premalignant stage of CRCs with MSI and CIMP, which could serve to improve the efficacy of colonoscopic surveillance.

Epigenetic alteration of DNA in mucosal wash fluid predicts invasiveness of colorectal tumors.

Although conventional colonoscopy is considered the gold standard for detecting colorectal tumors, accurate staging is often difficult because advanced histology may be present in small colorectal lesions. We collected DNA present in mucosal wash fluid from patients undergoing colonoscopy and then assessed the methylation levels of four genes frequently methylated in colorectal cancers to detect invasive tumors. We found that methylation levels in wash fluid were significantly higher in patients with invasive than those with noninvasive tumors. Cytologic and K-ras mutation analyses suggested that mucosal wash fluid from invasive tumors contained greater numbers of tumor cells than wash fluid from noninvasive tumors. Among the four genes, levels of mir-34b/c methylation had the greatest correlation with the invasion and showed the largest area under the receiver operating characteristic curve (AUC = 0.796). Using cutoff points of mir-34b/c methylation determined by efficiency considerations, the sensitivity/specificity were 0.861/0.657 for the 13.0% (high sensitivity) and 0.765/0.833 for the 17.8% (well-balanced) cutoffs. In the validation test set, the AUC was also very high (0.915), the sensitivity/specificity were 0.870/0.875 for 13.0% and 0.565/0.958 for 17.8%. Using the diagnostic tree constructed by an objective algorithm, the diagnostic accuracy of the invasiveness of colorectal cancer was 91.3% for the training set and 85.1% for the test set. Our results suggest that analysis of the methylation of DNA in mucosal wash fluid may be a good molecular marker for predicting the invasiveness of colorectal tumors.

Methylation-associated silencing of microRNA-34b/c in gastric cancer and its involvement in an epigenetic field defect.

Altered expression of microRNA (miRNA) is strongly implicated in cancer, and recent studies have shown that the silencing of some miRNAs is associated with CpG island hypermethylation. To identify epigenetically silenced miRNAs in gastric cancer (GC), we screened for miRNAs induced by treatment with 5-aza-2'-deoxycytidine and 4-phenylbutyrate. We found that miR-34b and miR-34c are epigenetically silenced in GC and that their downregulation is associated with hypermethylation of the neighboring CpG island. Methylation of the miR-34b/c CpG island was frequently observed in GC cell lines (13/13, 100%) but not in normal gastric mucosa from Helicobacter pylori-negative healthy individuals. Transfection of a precursor of miR-34b and miR-34c into GC cells induced growth suppression and dramatically changed the gene expression profile. Methylation of miR-34b/c was found in a majority of primary GC specimens (83/118, 70%). Notably, analysis of non-cancerous gastric mucosae from GC patients (n = 109) and healthy individuals (n = 85) revealed that methylation levels are higher in gastric mucosae from patients with multiple GC than in mucosae from patients with single GC (27.3 versus 20.8%; P < 0.001) or mucosae from H. pylori-positive healthy individuals (27.3 versus 20.7%; P < 0.001). These results suggest that miR-34b and miR-34c are novel tumor suppressors frequently silenced by DNA methylation in GC, that methylation of miR-34b/c is involved in an epigenetic field defect and that the methylation might be a predictive marker of GC risk.

[A patient with GM2 gangliosidosis presenting with motor neuron disease symptom in his forties].

Here, we report a Japanese man with adult Sandhoff disease who presented with a motor neuron disease phenotype with slow progression. At the age of 42, he noticed weakness in his legs. At the age of 46, he was admitted to our hospital. Neurological examination revealed muscle weakness and atrophy of the upper and lower extremities, and hyperreflexia of the upper extremities. Magnetic resonance imaging showed very mild cerebellar atrophy. We diagnosed him as having atypical amyotrophic lateral sclerosis. Because of the atypical course of motor neuron disease, hexosaminidase activity in peripheral leukocytes was indicated. Asseys of hexosaminidase A and hexosaminidase B showed low activities, and we found a membranous cytoplasmic body in the submucosal nerve, leading to the diagnosis of Sandhoff disease. This is the second case of a Japanese adult with Sandhoff disease presenting with a motor neuron disease phenotype, and to our knowledge, this is the latest age of onset in Japan.

[Two cases of generalized tetanus presenting with dysphagia as an initial symptom].

We describe two patients with generalized tetanus, a 60-year-old man and a 76-year-old woman, presenting with dysphagia as an initial symptom of the disease. Eighty percent of patients with generalized tetanus manifest dysphagia on admission to a hospital. However, dysphagia is rare as an initial symptom. Both our patients had dysphagia as their initial symptom, followed by neck stiffness and trismus. We made a diagnosis of generalized tetanus based on these neurological findings in the absence of an apparent episode of trauma. After the administration of tetanus immunoglobulin on admission, they recovered without exhibiting generalized convulsion, autonomic storm, or any other serious complications. The vaccination of tetanus toxoid cannot maintain sufficient antibody titers more than ten years. Therefore, elderly people are considered susceptible to tetanus. We suggest that tetanus should be considered in the differential diagnosis of dysphagia particularly in elderly patients. We also suggest that treatment of tetanus should be initiated immediately, because tetanus still has a high mortality rate at present.