Sang Bong Ahn

The Miss Rate for Colorectal Adenoma Determined by Quality-Adjusted, Back-to-Back Colonoscopies.

Background/Aims Colonoscopy is considered to be the gold standard for detecting adenomatous polyps. Polyps are missed during colonoscopic examination at a rate that varies from 6% to 27%. The adenoma miss rate affects colonoscopic surveillance intervals and procedural quality. We aimed to assess the adenoma miss rate and the variables affecting the rate using same-day, quality-adjusted, back-to-back colonoscopies. Methods This prospective study was performed at a single institution and included 149 patients. Two consecutive same-day colonoscopies were performed by two experienced endoscopists. The adenoma miss rates and variables affecting the missed adenomas, including polyp characteristics and procedure times, were evaluated. Results The miss rates of polyps, adenomas, and advanced adenomas were 16.8%, 17%, and 5.4%, respectively. The smaller polyps and increased number of polyps detected during the first colonoscopy were more likely to be missed. A longer insertion time during the colonoscopy was correlated with an increased adenoma detection rate. Conclusions There was a significant miss rate in the detection of colonic adenomas even in quality-adjusted, back-to-back colonoscopies. The adenoma miss rate can be reduced with a sufficient observation time during colonoscopic insertion. The development of specific technological methods to reduce the adenoma miss rate is necessary.

A Proton Pump Inhibitor's Effect on Bone Metabolism Mediated by Osteoclast Action in Old Age: A Prospective Randomized Study

Background/Aims Proton pump inhibitors (PPIs) act by irreversibly binding to the H+-K+-ATPase of the proton pump in parietal cells and may possibly affect the vacuolar H+-ATPase in osteoclasts. Methods We investigated the effect of 8 weeks of PPI treatment on the parameters of bone turnover and compared PPI with revaprazan, which acts by reversibly binding to H+-K+-ATPase in proton pumps. This study was a parallel randomized controlled trial. For 8 weeks, either a PPI or revaprazan was randomly assigned to patients with gastric ulcers. The parameters of bone turnover were measured at the beginning of and after the 8-week treatment period. Results Twenty-six patients (PPI, n=13; revaprazan, n=13) completed the intention-to-treat analysis. After the 8-week treatment period, serum calcium and urine deoxypyridinoline (DPD) were increased in the PPI group (serum calcium, p=0.046; urine DPD, p=0.046) but not in the revaprazan group. According to multivariate linear regression analysis, age ≥60 years was an independent predictor for the changes in serum calcium and urine DPD. Conclusions In elderly patients, administering a PPI for 8 weeks altered bone parameters. Our study suggested that PPIs might directly alter bone metabolism via the vacuolar H+-ATPase in osteoclasts.

Alcohol Drinking Increased the Risk of Advanced Colorectal Adenomas

Background/Aims Age, sex, gene and life style are modulating risks for colon cancer. Although alcohol intake may impact on colorectal adenoma, clear association has not been established yet. We aimed to investigate effects of alcohol consumption on the characteristics of colorectal adenoma. Methods Patients who underwent colonoscopic polypectomy of colorectal adenoma in the department of gastroenterology of Eulji hospital through 2005 to 2012, having both blood tests and ultrasound or abdominal CT examination were enrolled. The alcohol drinking patients were subdivided into normal or abnormal laboratory group, and alcoholic liver diseases group. Results 212 patients with colorectal adenoma were analyzed; advanced adenoma and multiple adenoma were found in 68 (32.0%) and 79 (37.2%) patients. When compared to the nondrinker group (120/212 patients), the alcohol drinker group (92/212 patients) represented significantly high odds ratios (ORs) for advanced adenoma (OR, 2.697; P=0.002), and multiple adenoma (OR, 1.929; P=0.039). Among alcohol drinker (92 patients), the ORs of advanced adenoma were 6.407 (P=0.003) in alcoholic liver diseases group (17 patients), 3.711 (P=0.002) in the alcohol drinker with abnormal lab (24 patients), and 2.184 (P=0.034), in the alcohol drinker with normal lab (51 patients) compared to nondrinker group. Conclusions This study showed that alcohol drinking may influence on the development of advanced colorectal adenoma and multiplicity. Especially in the group with alcoholic liver diseases and with abnormal lab presented significantly higher ORs of advanced adenoma.

Intramural gallbladder hematoma mimicking gallbladder neoplasm in a 55-year-old male patient.

Hemorrhage in the gallbladder (GB) is usually associated with cholecystitis, GB neoplasm, trauma, hemobilia, and cystic artery aneurysm. Our patient had not experienced any previous abdominal trauma, and GB hemorrhage was unlikely to result from cholecystitis or bleeding diathesis. A 55-year-old male was admitted because of right upper quadrant pain. Both prothrombin time and partial thromboplastin time were normal. Abdominal computed tomography, endoscopic ultrasound and magnetic resonance cholangiopancreatography were performed. Image studies revealed GB wall thickening and an intraluminal mass. Laparoscopic cholecystectomy was performed. Upon opening the GB postoperatively, a large amount of fresh blood and old blood clot was noted. The incidence of GB hematoma is very rare. GB hematoma should always be considered in the differential diagnosis of GB tumor. In such a situation, surgical intervention is needed for further patient evaluation and management. We present a rare case of intramural GB hematoma, of which we were unable to make a definitive diagnosis preoperatively.

A case of colon perforation due to enteropathy-associated T-cell lymphoma

Enteropathy-associated T-cell lymphoma (EATL) is an extremely rare disease, which is often related to gluten-sensitive enteropathy. It is an uncommon intestinal lymphoma with very poor prognosis and high mortality rate. In the absence of specific symptoms or radiological findings, it is difficult to diagnose early. Major complications of EATL have been known as intestinal perforation or obstruction, and only 5 cases of EATL are reported in South Korea. In this study, we report a case of 71-year-old male with symptoms of diarrhea, which later it progressed into cancer perforation of the colon. The initial colonoscopic findings were normal and computed tomography scan demonstrated a segmental wall thickening of the distal ascending colon with nonspecific multiple small lymphnodes, along the ileocolic vessels, but no signs of mass or obstruction. The histologic findings of resected specimen confirmed EATL type II. Patient expired two weeks after the operation. Therefore, we emphasize the need of random biopsy in the presence of normal mucosa appearance on colonoscopy for the early diagnosis of EATL.

A Case of Colonic Mucinous Adenocarcinoma in 19-year-old Male Patient

Colorectal cancer is rare in teenagers, especially without known risk factors. Colon cancer in young age is more likely to be diagnosed at advanced-stage, to present unfavorable tumor histology such as mucinous carcinoma, and poor outcome. We report a case of sporadic mucinous adenocarcinoma of the colon in a 19-year-old male patient without any risk factors. He complained of severe left abdominal pain that developed 1 month ago. He had a distended abdomen with severe tenderness on the left lower quadrant. A distal descending colon mass causing mechanical obstruction was observed on abdominal computed tomography. Emergency colonoscopy showed a large, fungating mass obstructing the lumen at 40 cm from the anal verge. Biopsy of the colonic mass suggested a mucinous adenocarcinoma. After decompression by colonic stent, the patient was transferred to the general surgery department for left hemicolectomy. The lesion was confirmed to be a mucinous adenocarcinoma (7.0×4.5 cm). For hereditary nonpolyposis colorectal cancer evaluation, immunohistochemical staining for MLH1 and MSH2 was normal. Reverse transcription polymerase chain reaction analysis did not detect microinstability in any of the markers tested. The patient had no familial history of cancer. Mucinous adenocarcinoma has high frequencies of poor differentiation, advanced tumor stage, loss of mismatch repair gene expression, and increased MUC2 expression. A mucinous histology is considerably more frequent in children and adolescent than in adults. Adequate invasive study is also necessary for young age patients.

A case of eosinophilic esophagitis with food hypersensitivity.

Eosinophilic esophagitis (EoE) is a disorder characterized by isolated eosinophilic infiltration of the esophagus with esophageal symptoms. Although some patients with EoE are related to food hypersensitivity, it is hard to identify causative foods. This report describes a case of EoE with dysphagia. A 28-year-old man presented with dysphagia and substernal discomfort for 15 days. He had taken a protein complex for 2 months. Endoscopy showed several linear furrows and multiple mucosal nodularities on the lower and mid esophagus, and the biopsies of esophagus revealed marked eosinophil infiltration in the mucosa. The skin testing for the protein complex was positive. The patient was successfully treated with withholding treatment.

Diaphragm disease compared with cryptogenic multifocal ulcerous stenosing enteritis.

As the use of drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs) increases, so too do gastrointestinal ulcers, bleeding, perforation and obstruction. Diaphragm disease of the small intestine is formed by submucosal fibrosis and destruction of lamina muscularis due to chronic ulceration, which corresponds to the most severe stage of NSAID enteropathy. It may lead to stricture of the small intestine. If such ulcerations and strictures in the small intestine are multiple, differential diagnosis is between diaphragm disease and cryptogenic multifocal ulcerous stenosing enteritis (CMUSE), because the gross findings of diaphragm disease are similar to those of CMUSE. We report a rare case of diaphragm disease caused by NSAID. It has been finally confirmed by capsule endoscopy and the origin of chronic obscure gastrointestinal bleeding was found to be multiple ulcers and strictures in the small intestine. After operation, we diagnosed the patient with diaphragm disease rather than CMUSE.

Pseudoinvasion in an Adenomatous Polyp of the Colon Mimicking Invasive Colon Cancer

Pseudoinvasion or pseudocarcinomatous invasion in an adenomatous polyp of the colon can be unfamiliar to an endoscopist. Pseudoinvasion in an adenomatous polyp represents prolapse of the adenomatous epithelium into its stalk. In most cases its morphology does not differ from of general adenomatous polyps, but in some cases it can morphologically mimic a malignant polyp with submucosal invasion due to mass-like lesioning of its stalk. This makes it difficult for endoscopists to differentiate pseudoinvasion in an adenoma from an invasive carcinoma by conventional endoscopy; instead, endoscopic ultrasonography can provide useful information for differentiating these conditions. We report on an 82-year-old man who presented with a large pedunculated polyp with a thick stalk in the sigmoid colon, which mimicked a submucosal invasive carcinoma. The patient was diagnosed with pseudoinvasion in an adenomatous polyp after segmental resection of the sigmoid colon.

Increased risk of asymptomatic gallstones in patients with ulcerative colitis.

Background/Aims The relationship between Crohns disease and gallstones is established. However, the prevalence and risk factors for gallstones in patients with ulcerative colitis (UC) are not yet well understood. The aim of this study was to evaluate the prevalence and risk factors of gallstones in patients with UC. Methods This study was a retrospective single center study. A total of 87 patients with UC and 261 healthy controls were enrolled. Age, sex, and body mass index were matched. To investigate risk factors, the extent of UC, duration of disease, number of hospital admissions, and number of steroid treatments in patients with UC were evaluated. Results The prevalence of gallstones in patients with UC was 13.8%, whereas that in healthy controls was only 3.1% (P<0.001). For patients with UC, patients ≥50 years of age had a 3.6-times higher risk of gallstones compared to that in those <50 years of age, and the difference was statistically significant (odds ratio, 3.60; confidence interval, 1.03-12.61) in univariate analysis. There were no statistically significant disease-related risk factors for gallstones in UC patients. Conclusions This is the first study of gallstone prevalence in Korean UC patients. In this study, patients with UC had a higher prevalence of gallstones compared to that in well-matched healthy controls. Age seemed to be a possible risk factor, and more studies are needed. Further prospective, large-scale studies will be required to confirm the risk factors for gallstones in UC patients.