Development and validation of a scoring system for advanced colorectal neoplasm in young Korean subjects less than age 50 years

BACKGROUND/AIMS: Colorectal cancer incidence among patients aged ≤50 years is increasing. This study aimed to develop and validate an advanced colorectal neoplasm (ACRN) screening model for young adults aged <50 years in Korea. METHODS: This retrospective cross-sectional study included 59,575 consecutive asymptomatic Koreans who underwent screening colonoscopy between 2003 and 2012 at a single comprehensive health care center. Young Adult Colorectal Screening (YCS) score was developed as an optimized risk stratification model for ACRN using multivariate analysis and was internally validated. The predictive power and diagnostic performance of YCS score was compared with those of Asia-Pacific Colorectal Screening (APCS) and Korean Colorectal Screening (KCS) scores. RESULTS: 41,702 and 17,873 subjects were randomly allocated into the derivation and validation cohorts, respectively, by examination year. ACRN prevalence was 0.9% in both cohorts. YCS score comprised sex, age, alcohol, smoking, obesity, glucose metabolism abnormality, and family history of CRC, with score ranges of 0 to 10. In the validation cohort, ACRN prevalence was 0.6% in the low-risk tier (score, 0–4), 1.5% in the moderate-risk tier (score, 5–7), and 3.4% in the high-risk tier (score, 8–10). ACRN risk increased 2.5-fold (95% confidence interval [CI], 1.8–3.4) in the moderate-risk tier and 5.8-fold (95% CI, 3.4–9.8) in the high-risk tier compared with the low-risk tier. YCS score identified better balanced accuracy (53.9%) than APCS (51.5%) and KCS (50.7%) scores and had relatively good discriminative power (area under the curve=0.660). CONCLUSIONS: YCS score based on clinical and laboratory risk factors was clinically effective and beneficial for predicting ACRN risk and targeting screening colonoscopy in adults aged <50 years.

External Validation of the Endoscopic Features of Sessile Serrated Adenomas in Expert and Trainee Colonoscopists

BACKGROUND/AIMS: It is unclear whether the endoscopic features of sessile serrated adenomas (SSAs) would be useful to trainee colonoscopists to predict SSA. Therefore, the present study aimed to identify features that expert and trainee colonoscopists can use to independently and reliably predict SSA by using high-resolution white-light endoscopy. METHODS: Endoscopic images of 81 polyps (39 SSAs, 22 hyperplastic polyps, and 20 tubular adenomas) from 43 patients were retrospectively evaluated by 10 colonoscopists (four experts and six trainees). Eight endoscopic features of SSAs were assessed for each polyp. RESULTS: According to multivariable analysis, a mucous cap (odds ratio [OR], 10.44; 95% confidence interval [CI], 5.72 to 19.07), indistinctive borders (OR, 4.21; 95% CI, 2.74 to 7.16), dark spots (OR, 3.64; 95% CI, 1.89 to 7.00), and cloud-like surface (OR, 2.43; 95% CI, 1.27 to 4.668) were independent predictors of SSAs. Among these, a mucous cap, indistinctive borders, and cloud-like surface showed moderate interobserver agreement (mean κ>0.40) among experts and trainees. When ≥1 of the three predictors was observed, the sensitivity and specificity for diagnosing SSAs were 79.0% and 81.4%, respectively. CONCLUSIONS: Colonoscopy trainees and experts can use several specific endoscopic features to independently and reliably predict SSAs.

Is methylation analysis of SFRP2, TFPI2, NDRG4, and BMP3 promoters suitable for colorectal cancer screening in the Korean population?

BACKGROUND/AIMS: Colorectal cancer (CRC) screening using stool DNA was recently found to yield good detection rates. A multi-target stool DNA test (Cologuard®, Exact Sciences), including methylated genes has been recently approved by the U.S. Food and Drug Administration. The aim of this study was to validate these aberrantly methylated genes as stool-based DNA markers for detecting CRC and colorectal advanced adenoma (AA) in the Korean population. METHODS: A single-center study was conducted in 36 patients with AA; 35 patients with CRC; and 40 endoscopically diagnosed healthy controls using CRC screening colonoscopy. The methylation status of the SFRP2, TFPI2, NDRG4, and BMP3 promoters was investigated blindly using bisulfate-modified stool DNA obtained from 111 participants. Methylation status was investigated by methylation-specific polymerase chain reaction. RESULTS: Methylated SFRP2, TFPI2, NDRG4, and BMP3 promoters were detected in 60.0%, 31.4%, 68.8%, and 40.0% of CRC samples and in 27.8%, 27.8%, 27.8%, and 33.3% of AA samples, respectively. The sensitivities obtained using 4 markers to detect CRC and AA were 94.3% and 72.2%, respectively. The specificity was 55.0%. CONCLUSIONS: Our results demonstrate that the SFRP2, TFPI2, NDRG4, and BMP3 promoter methylation analysis of stool sample DNA showed high sensitivity but low specificity for detecting CRC and AA. Because of the low specificity, 4 methylated markers might not be sufficient for CRC screening in the Korean population. Further large-scale studies are required to validate the methylation of these markers in the Asian population and to find new markers for the Asian population.

Erratum: Field Cancerization in Sporadic Colon Cancer

In the version of this article initially published, the first affiliation (affiliation number 1) was incorrectly stated as "Division of Gastroentorology, Department of Internal Medicine." The correct affiliation is "Department of Internal Medicine."

Field Cancerization in Sporadic Colon Cancer

BACKGROUND/AIMS: Aberrant DNA methylation has a specific role in field cancerization. Certain molecular markers, including secreted frizzled-related protein 2 (SFRP2), tissue factor pathway inhibitor 2 (TFPI2), N-Myc downstream-regulated gene 4 (NDRG4) and bone morphogenic protein 3 (BMP3), have previously been shown to be hypermethylated in colorectal cancer (CRC). We aim to examine field cancerization in CRC based on the presence of aberrant DNA methylation in normal-appearing tissue from CRC patients. METHODS: We investigated promoter methylation in 34 CRC patients and five individuals with normal colonoscopy results. CRC patients were divided into three tissue groups: tumor tissue, adjacent and nonadjacent normal-appearing tissue. The methylation status (positive: methylation level >20%) of SFRP2, TFPI2, NDRG4, and BMP3 promoters was investigated using methylation-specific PCR. RESULTS: The methylation frequencies of the SFRP2, TFPI2, NDRG4 and BMP3 promoters in tumor/adjacent/nonadjacent normal-appearing tissue were 79.4%/63.0%/70.4%, 82.4%/53.6%/60.7%, 76.5%/61.5%/69.2%, 41.2%/35.7%/50.0%, respectively. The methylation levels of the SFRP,TFPI2, NDRG4 and BMP3 promoters in tumor tissues were significantly higher than those in normal-appearing tissue (SFRP2, p=0.013; TFPI2, p<0.001; NDRG4, p=0.003; BMP3, p=0.001). No significant correlation was observed between the methylation levels of the promoters and the clinicopathological variables. CONCLUSIONS: The field effect is present in CRC and affects both the adjacent and nonadjacent normal-appearing mucosa.

Microsatellite Instability Status of Interval Colorectal Cancers in a Korean Population

BACKGROUND/AIMS: A subset of patients may develop colorectal cancer after a colonoscopy that is negative for malignancy. These missed or de novo lesions are referred to as interval cancers. The aim of this study was to determine whether interval colon cancers are more likely to result from the loss of function of mismatch repair genes than sporadic cancers and to demonstrate microsatellite instability (MSI). METHODS: Interval cancer was defined as a cancer that was diagnosed within 5 years of a negative colonoscopy. Among the patients who underwent an operation for colorectal cancer from January 2013 to December 2014, archived cancer specimens were evaluated for MSI by sequencing microsatellite loci. RESULTS: Of the 286 colon cancers diagnosed during the study period, 25 (8.7%) represented interval cancer. MSI was found in eight of the 25 patients (32%) that presented interval cancers compared with 22 of the 261 patients (8.4%) that presented sporadic cancers (p=0.002). In the multivariable logistic regression model, MSI was associated with interval cancer (OR, 3.91; 95% confidence interval, 1.38 to 11.05). CONCLUSIONS: Interval cancers were approximately four times more likely to show high MSI than sporadic cancers. Our findings indicate that certain interval cancers may occur because of distinct biological features.

Factors Associated with Anxiety and Depression in Korean Patients with Inactive Inflammatory Bowel Disease

BACKGROUND/AIMS: Psychological distress is highly prevalent in patients with inflammatory bowel disease (IBD). We evaluated the disease characteristics and socioeconomic factors associated with anxiety and depression in Korean patients with quiescent IBD. METHODS: In total, 142 IBD patients (67 with Crohn's disease [CD] and 75 with ulcerative colitis [UC]) completed self-report questionnaires, including the Hospital Anxiety and Depression Score, the Modified Morisky Adherence Scale-8, the socioeconomic deprivation score, and the Crohn's and Colitis Knowledge Score questionnaires. RESULTS: In the CD group, 30 patients (44%) were anxious, and 10 patients (15%) were depressed; in the UC group, 31 patients (41%) were anxious, and 18 patients (24%) were depressed. Using multivariate analysis, in the CD group, socioeconomic deprivation was associated with anxiety (p=0.03), whereas disease duration (p=0.04) and socioeconomic deprivation (p=0.013) were associated with depression. In the UC group, there was no significant independent predictor of anxiety and/or depression; however, low income tended to be associated with depression (p=0.096). CONCLUSIONS: Despite clinical remission, a significant number of IBD patients present with anxiety and depression. IBD patients in remission, particularly those who are socioeconomically deprived, should be provided with appropriate psychological support.

Comparison of the clinical outcomes between antiviral-naïve patients treated with entecavir and lamivudine-resistant patients receiving adefovir add-on lamivudine combination treatment

BACKGROUND/AIMS: To analyze the effects of preexisting lamivudine (LAM) resistance and applying antiviral treatment (adefovir [ADV] add-on LAM combination treatment) on long-term treatment outcomes, and comparing the clinical outcomes of antiviral-naïve chronic hepatitis B patients receiving entecavir (ETV) monotherapy. METHODS: This study enrolled 73 antiviral-naïve patients who received 0.5-mg ETV as an initial therapy and 54 patients who received ADV add-on LAM combination treatment as a rescue therapy from July 2006 to July 2010. RESULTS: During 24-month treatments, the decreases in serum log10HBV-DNA values (copies/mL) were significantly greater in the antiviral-naïve patients treated with ETV than the patients receiving ADV add-on LAM combination treatment. The biochemical response rates for alanine aminotransferase normalization at 6 months (ETV) and 12 months (ADV add-on LAM) were 90.4% (66/73) and 77.8% (42/54), respectively (P=0.048). A Kaplan-Meier analysis indicated that the rates of serologic response, viral breakthrough, and emergence of genotypic resistance did not differ significantly between the two patient groups. There were also no significant intergroup differences in the rates of disease progression (PD) and new development of hepatocellular carcinoma (HCC). CONCLUSION: The long-term clinical outcomes of antiviral-naïve patients treated with ETV and LAM-resistant patients receiving ADV add-on LAM combination treatment were comparable in terms of the emergence of HCC and disease progression.

A Case of Mixed Adenoneuroendocrine Carcinoma of the Common Bile Duct: Initially Diagnosed as Cholangiocarcinoma

No abstract available.

Applying Novel Nutrient Drink to Clinical Trial of Functional Dyspepsia

BACKGROUND/AIMS: The drink test has been regarded as a surrogate marker of gastric accommodation. The aims of this study were to develop a novel nutrient drink test (NDT) protocol and investigate its potential for application to a clinical trial of functional dyspepsia (FD). METHODS: A novel NDT was designed, involving drinking 125 mL of nutrient 4 times at 5-minute intervals or until maximal tolerability. Healthy volunteers and patients with FD rated their symptoms every 5 minutes for 20 minutes in a developmental study. Patients with FD were enrolled in an open trial of itopride for 4 weeks. NDT was performed before and after treatment. Improvement of integrative symptoms score during NDT after treatment for more than 50% compared with baseline was defined as responder. RESULTS: Total aggregate symptom scores, sum of symptom scores measured during NDT, were higher in FD patients (n = 40, 368.1 +/- 245.3) than in controls (n = 19, 215.9 +/- 171.2) (P = 0.018) in a developmental study. In an open trial of itopride, symptom scores measured during NDT decreased significantly at all time points after treatment in responders (n = 49), whereas did not in non-responders (n = 25). Total aggregate symptom score for NDT correlated significantly with integrative dyspeptic symptom score, sum of 8 symptom scores of NDI questionnaire, at baseline (r = 0.374, P = 0.001) and after treatment (r = 0.480, P < 0.001). CONCLUSIONS: Our novel NDT can quantify dyspeptic symptoms and reflected therapeutic effects of itopride treatment in a clinical trial of FD patients. This NDT can be used as an effective parameter in clinical trials or drug development programs for assessing effects of novel therapies on postprandial symptoms.

Efficacy of Bisacodyl Given as Part of a Polyethylene Glycol-based Bowel Preparation Prior to Colonoscopy in Hospitalized Patients: A Prospective Ramdomized Trial / 대한소화기학회지

BACKGROUND/AIMS: Inpatient status can cause inadequate bowel preparation. The majority of previous studies regarding bowel preparation have focused on comparing the effects of different purgative regimens in outpatients. However, data on bowel preparation for inpatients are lacking. The aim of this study was to investigate whether bisacodyl plus polyethylene glycol (PEG) can improve bowel preparation in hospitalized patients. METHODS: A prospective, randomized and observer-blind study was performed. A total of 196 hospitalized patients undergoing colonoscopy were randomized to receive 4 L PEG (PEG only group) or 4 L PEG+bisacodyl 10 mg (bisacodyl added group). The adequacy of bowel preparation was scored using the Ottawa bowel preparation scale. RESULTS: One hundred and eighty-three subjects completed the study; 96 in the bisacodyl added group and 87 in the PEG only group. There were no significant differences between the bisacodyl added group and the PEG only group with respect to the score of bowel cleansing (3.59+/-2.81 vs. 3.82+/-3.03, p=0.607), quality of bowel cleansing (adequate preparation 89.6% vs. 85.1%, p=0.380), and overall adverse events (66.7% vs. 52.9%, p=0.057). However, a larger proportion of patients in the PEG only group were able to ingest the entire solution as prescribed than in the bisacodyl added group (98.9% vs. 75.0%, p<0.001). CONCLUSIONS: In hospitalized patients, the quality of bowel preparation did not differ depending on whether bisacodyl is added or not. In addition, patient compliance based on consumption of cleansing agent was better in the PEG only group.

Symptom Characteristics and Psychosomatic Profiles in Different Spectrum of Gastroesophageal Reflux Disease

BACKGROUND/AIMS: Gastroesophageal reflux disease (GERD) is diagnosed based on symptoms of heartburn and regurgitation but is a heterogeneous condition which can be subclassified according to endoscopy and esophageal reflux monitoring. The aim of this study was to identify differences in demographic characteristics and reflux symptom patterns among patients with various spectrum of GERD. METHODS: Patients having weekly heartburn or acid regurgitation were classified into four pathophysiological subgroups according to endoscopy and pH monitoring: reflux esophagitis (RE), endoscopy-negative reflux disease with pathological reflux (PR+), hypersensitive esophagus (HE), and normal acid exposure with negative symptom association (pH-). RESULTS: A total of 195 patients were enrolled. The numbers of patients in the subgroups were: RE, 39.0%; PR+, 20.0%; HE, 10.3%; and pH-, 30.8%. Grossly, reflux symptom patterns and relieving/exacerbating factors did not differ between subgroups. Prevalence of extraesophageal syndrome was higher in patients with PR+ than in other groups. Overlapping functional dyspepsia was common in all groups. The SCL-90-R depression score was higher in PR+ patients than in RE patients (p<0.05). CONCLUSIONS: Demographic characteristics and reflux symptom patterns cannot differentiate pH- group from GERD subtypes. Esophageal pH monitoring could be considered for the initial evaluation of GERD in the tertiary referral setting.

The Temporary Placement of Covered Self-Expandable Metal Stents to Seal Various Gastrointestinal Leaks after Surgery

Gastrointestinal leakage is one of the most serious post surgical complications and is a major source of mortality and morbidity. The insertion of a covered self-expandable metal stent could be a treatment option in selected cases. However, it is unclear how long the stent should be retained to achieve complete sealing, and membrane-covered stents have the problem of a high migration rate. We observed four cases of postsurgical leakage following the primary closure of a duodenal perforation, esophagojejunostomy, and esophagogastrostomy, each of which was successfully managed by the temporary placement of covered stents. In all cases, the optimal time of stent removal could be estimated by the markedly decreased amount of drainage, the lack of leakage observed on radiocontrast images, and the endoscopic findings. In this case series, all of the stents could be removed within 7 weeks. For those cases with a high risk of migration, stents with temporary fixations to earlobes and/or partially uncovered proximal flanges were used. These results suggest that the application of a covered stent could be a treatment option for various gastrointestinal leaks after surgery, particularly when the defect cannot be sealed by conservative care and the leakage has good external drainage.

Obesity Is Associated With Increasing Esophageal Acid Exposure in Korean Patients With Gastroesophageal Reflux Disease Symptoms

BACKGROUND/AIMS: Obesity is regarded as an important contributor to the increasing occurrence of gastroesophageal reflux disease. The aims of this study were to determine whether obesity is associated with gastroesophageal reflux in patients with gastroesophageal reflux disease and to identify the factors affecting increased acid exposure in obese patients. METHODS: We retrospectively analyzed the data of patients who underwent ambulatory 24-hour pH monitoring and esophageal manometry at Seoul St. Mary's Hospital. Obesity was classified according to the Asia-Pacific criteria. RESULTS: A total of 366 patients were analyzed; 18 were underweight, 152 normal weight, 104 overweight, and 92 obese. Obesity was more frequent in men and younger patients. The percentage time of pH < 4 in the total, upright, and postprandial periods was significantly higher in obese patients than in normal or underweight patients. The DeMeester score was also higher in obese patients. Body mass index correlated positively with reflux parameters. Multivariate analysis showed that being male and obesity were significantly associated with abnormal acid exposure (P < 0.005). The total lower esophageal sphincter length shortened as body mass index increased (P < 0.005). The gastroesophageal pressure gradient increased as body mass index increased (P < 0.05). CONCLUSIONS: Obesity is associated with increasing esophageal acid exposure. The mechanism responsible for the relationship between gastroesophageal reflux disease and obesity may be associated with shortening of the lower esophageal sphincter length and increasing the gastroesophageal pressure gradient.

Performance and Clinical Role of Endoscopic Ultrasound Fine Needle Aspiration for Diagnosing Gastrointestinal Intramural Lesions

BACKGROUND/AIMS: We evaluated the performance, clinical role, and diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in gastrointestinal intramural lesions. METHODS: Procedural and pathologic data were reviewed from consecutive patients undergoing EUS-FNA for intramural lesions. Final diagnoses were determined by surgical histopathologic conformation and the diagnosis of malignancy, including clinical follow-up with repeat imaging. RESULTS: Forty-six patients (mean age, 47 years; 24 males) underwent EUS-FNA. Lesions were located in the stomach (n=31), esophagus (n=5), and duodenum (n=10). The median lesion size was 2 cm (range, 1 to 20.6). Final diagnoses were obtained in 22 patients (48%). EUS-FNA was diagnostic in 40 patients (87%). The diagnostic accuracy of cytology for differentiating between benign and malignant lesions was 82%; diagnostic error occurred in three patients (6%). The cytologic results influenced clinical judgment in 78% cases. The primary reasons for negative or no clinical impact were false-negative results, misdirected patient management, and inconclusive cytology. CONCLUSIONS: EUS-FNA exhibited an 87% diagnostic yield for gastrointestinal intramural lesions; the accuracy of cytology for differentiating malignancy was 82%. The limitations of EUS-FNA were primarily because of nondiagnostic sampling (9%) and probable diagnostic error (6%); these factors may influence the clinical role of EUS-FNA.

Diagnostic Accuracy and Interobserver Agreement in Predicting the Submucosal Invasion of Colorectal Tumors Using Gross Findings, Pit Patterns, and Microvasculatures

BACKGROUND/AIMS: Depth of invasion is one of the most important factors for establishing treatment strategy for colorectal tumors. METHODS: Three blinded experts reviewed electronic photos and video clips of 33 early colorectal cancer-like lesions. They estimated the depth of invasion based on conventional white light endoscopy (CWE), magnifying chromoendoscopy (MCE), and magnifying narrow band imaging endoscopy (MNE). RESULTS: The lesions included nine mucosal low-grade neoplasias, 16 mucosal high grade neoplasias, and eight carcinomas with invasion to the submucosal layer or beyond. The diagnostic accuracy for submucosal invasion by CWE ranged from 67% to 82%, while those by MCE and MNE ranged from 85% to 88% and 85% to 88%, respectively. The diagnostic accuracy significantly differed between CWE and MCE (p=0.034) and between CWE and MNE (p=0.039). The kappa values for CWE, MCE, and MNE among the endoscopists were 0.564, 0.673, and 0.673, respectively. CONCLUSIONS: The estimation of submucosal invasion for early colorectal cancer-like lesions based on MCE or MNE is more accurate than CWE. MCE and MNE were demonstrated to have substantial agreement for predicting submucosal invasion.

Performance and Cost of Disposable Biopsy Forceps in Upper Gastrointestinal Endoscopy: Comparison with Reusable Biopsy Forceps

BACKGROUND/AIMS: It is believed that disposable biopsy forceps are more costly than reusable biopsy forceps. In this study, we evaluated performance and cost of disposable forceps versus reusable forceps in esophagogastroduodenoscopic biopsy. METHODS: Between October 2009 and July 2010, we enrolled 200 patients undergoing esophagogastroduodenoscopic biopsy at Seoul St. Mary's Hospital. Biopsies were performed with 100 disposable or 5 reusable forceps by random assignment. Seventy-five additional patients were studied to estimate durability of reusable forceps. The assisting nurses estimated the performance of the forceps. The evaluation of costs included purchase prices and reprocessing costs. The adequacy of the sample was estimated according to the diameter of the obtained tissue. RESULTS: Performance of disposable forceps was estimated as excellent in 97.0%, good in 2.0% and adequate in 1.0%. Reusable forceps were estimated as excellent in 36.0%, good in 36.0%, adequate in 25.1% and inadequate in 2.9%. The performance of reusable forceps declined with the number of uses. The reprocessing cost of reusable forceps for one biopsy session was calculated as 8,021won. The adequacy of the sample was excellent for both forceps. CONCLUSIONS: Disposable forceps showed excellent performance. Considering the reprocessing costs of reusable forceps, usage of disposable forceps with a low price should be considered.

Association Between Toll-Like Receptors/CD14 Gene Polymorphisms and Inflammatory Bowel Disease in Korean Population

The innate immune response in patients who develop inflammatory bowel disease (IBD) may be abnormal. However, the exact role of Toll-like receptors (TLRs) / CD14 gene in the pathogenesis of IBD has not been fully elucidated. We aimed to investigate the association between polymorphisms of TLR1, 2, 4, 6, and CD14 gene and susceptibility to IBD in Korean population. A total 144 patients of IBD (99 patients with ulcerative colitis, 45 patients with Crohn's disease) and 178 healthy controls were enrolled. Using a PCR-RFLP, we evaluated mutations of TLR1 (Arg80Thr), TLR2 (Arg753Gln and Arg677Trp), TLR4 (Asp299Gly and Thr399Ile), TLR6 (Ser249Pro) genes and the -159 C/T promoter polymorphism of CD14 gene. No TLR polymorphisms were detected in Korean subjects. T allele and TT genotype frequencies of CD14 gene were significantly higher in IBD patients than in healthy controls. In subgroup analysis, T allelic frequency was higher in pancolitis phenotype of ulcerative colitis. In Korean population, the promoter polymorphism at -159 C/T of the CD14 gene is positively associated with IBD, both ulcerative colitis and Crohn's disease.

Two Cases of Gastric MALT Lymphoma Diagnosed at Long Last after Successful Eradication of Helicobacter pylori

The gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is a rare disease. Helicobacter pylori infection is known as an important etiologic factor of the pathogenesis of MALT lymphoma. H. pylori colonization at the epithelium of gastric mucosa induces T cell and B cell recruitment. T cell induced B cell proliferation develops the MALT in the gastric mucosa. Monoclonal proliferation of B cell in the MALT transform into MALT lymphoma. The eradication of H. pylori is known to induce remission of the disease in more than 80% of patients. But there is no report on progression and development of MALT lymphoma after H. pylori eradication. We experienced two cases of gastric B cell MALT lymphoma diagnosed at long last, after the successful eradication of H. pylori.

Two Cases of Gastric MALT Lymphoma Diagnosed at Long Last after Successful Eradication of Helicobacter pylori

The gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is a rare disease. Helicobacter pylori infection is known as an important etiologic factor of the pathogenesis of MALT lymphoma. H. pylori colonization at the epithelium of gastric mucosa induces T cell and B cell recruitment. T cell induced B cell proliferation develops the MALT in the gastric mucosa. Monoclonal proliferation of B cell in the MALT transform into MALT lymphoma. The eradication of H. pylori is known to induce remission of the disease in more than 80% of patients. But there is no report on progression and development of MALT lymphoma after H. pylori eradication. We experienced two cases of gastric B cell MALT lymphoma diagnosed at long last, after the successful eradication of H. pylori.