Yutaro Egashira

Comparative study of conventional colonoscopy and pan-colonic narrow-band imaging system in the detection of neoplastic colonic polyps: a randomized, controlled trial.

Background. Detection and removal of adenomas by colonoscopy is an important means for preventing cancer; however, small adenomas may be missed during colonoscopy. The narrow-band imaging (NBI) system clearly enhances the microvasculature in neoplastic lesions, making it appear as a dark complex. Therefore, the NBI system may improve the detection of colonic neoplasias. However, no randomized, controlled trials have evaluated the efficacy of a pan-colonic NBI system in adenoma detection. We conducted a randomized, controlled trial to determine the efficacy of the pancolonic NBI system in adenoma detection. Methods. Two hundred forty-three patients were randomized, 121 to conventional colonoscopy and 122 to pan-colonic NBI system. Demographics, indication for colonoscopy, and quality of preparation were similar between groups. Results. Extubation time was not significantly different between the conventional colonoscopy and pan-colonic NBI system. The proportions of patients with at least one adenoma and those with multiple adenomas were not significantly different between groups. However, the pan-colonic NBI system significantly increased the total number of adenomas detected (P < 0.05) and the number of diminutive (<5 mm) adenomas detected (P < 0.05). The pan-colonic NBI system allowed detection of more diminutive adenomas in the distal colon than did conventional colonoscopy (P < 0.01), and more patients in the NBI group had at least one diminutive adenoma than in the control group (P < 0.05). Conclusions. The pan-colonic NBI system improves the total number of adenomas detected, including significantly more diminutive adenomas, without prolongation of extubation time. These results indicate that routine use of the NBI system for surveillance of diminutive adenomas may be recommended.

MUCIN HISTOCHEMICAL ANALYSIS OF MINUTE GASTRIC DIFFERENTIATED ADENOCARCINOMA

Fifty‐six surgically resected intramucosal differentiated adenocarcinomas (DA) of the stomach with a maximum diameter of less than 5 mm were analyzed by mucin histochemistry. Gastric type phenotypic expression was observed in 41.1% of cases, intestinal type in 28.6% and gastric–intestinal type in 28.6% of all cancers. Gastric type phenotypic expression was the most frequent. As the tumor diameter increased, the incidence of DA with gastric phenotype tended to decrease. Intestinal metaplasia of the cancer’s surrounding mucosa was absent or slight in DA with gastric phenotype, but moderate to severe in DA with gastric–intestinal phenotype and intestinal phenotype. Morphologically and mucin histochemically, intestinal metaplasia surrounding DA with gastric phenotype was immature and incomplete compared with DA with gastric– intestinal phenotype or intestinal phenotype. It is suggested that a large amount of DA with gastric phenotype is histogenetically derived from the gastric gland proper without intestinal metaplasia. However, as the tumor grows and intestinal metaplasia progresses, intestinal type phenotypic expression appears and then DA with gastric phenotype changes into DA with gastric–intestinal phenotype or intestinal phenotype.

Preoperative Evaluation of Local Invasion and Metastatic Lymph Nodes of Colorectal Cancer and Mesenteric Vascular Variations Using Multidetector-Row Computed Tomography Before Laparoscopic Surgery

Objective: To evaluate local invasion and lymph nodes metastasis of colorectal cancer and mesenteric vascular variations using multidetector-row computed tomography (MDCT) before laparoscopic colorectal surgery. Methods: Fifty-one patients with colorectal cancer underwent MDCT. The evaluation items were as follows: (1) local invasion; (2) detected lymph nodes evaluated by short-axis diameter, long-axis diameter, short/long axis diameter ratio, and computed tomography (CT) attenuation; and (3) visualization of mesenteric artery and vein by 3-dimensional-CT angiography. Results: First, in the evaluation of local invasion, overall accuracy was 94.1%. Second, the point of 0.8 or greater in short/long-axis diameter ratio was best index for the diagnosis of metastatic lymph nodes. Using this index, the accuracy of the diagnosis per node was 80.5%. Third, 3-dimensional-CT angiography correctly demonstrated variations of the mesenteric artery and vein. Conclusions: The MDCT was effective for evaluation of local invasion and lymph nodes metastasis of colorectal cancer and mesenteric vascular variations before laparoscopic surgery.

Study of clinicopathological factors associated with the occurrence of synchronous multiple gastric carcinomas

BackgroundMultiple gastric carcinomas often arise in gastric mucosa with chronic gastritis, particularly severe intestinal metaplasia. In regard to such characteristics, several clinicopathological risk factors for multiple carcinomas have been reported, but no clinically useful criteria are available at present for assessing the onset of multiple gastric carcinomas. If the risk for multiple gastric carcinomas could be accurately assessed, efficient and accurate surveillance could be performed following minimally invasive therapies.MethodsIn the present study, we investigated clinicopathological differences between 94 cases of multiple early gastric carcinomas and 285 cases of solitary early gastric carcinoma. We tested 379 specimens of gastric carcinomas that had been surgically resected at the Department of General and Gastroenterological Surgery of Osaka Medical College, Japan, from April 1999 to December 2006.ResultsUnivariate analysis of clinicopathological factors in the present study showed that multiple gastric carcinomas were significantly correlated to old age (≥65 years), well- and moderately differentiated histological type, mucin phenotype (intestinal type), distribution of atrophic mucosa in the stomach (severe), degree of intestinal metaplasia in the surrounding mucosa (severe), and heterotopic glandular cysts. Multivariate analysis using the stepwise method identified age (≥65 years) and degree of intestinal metaplasia in the surrounding mucosa (severe) as significant independent risk factors for multiple gastric carcinomas.ConclusionWhile other studies have shown risk factors for multiple gastric carcinomas, the present study is unique in showing risk assessment criteria based on a combination of risk factors for multiple gastric carcinomas.

Adenocarcinoma arising in a heterotopic pancreas (Heinrich type III): a case report

IntroductionHeterotopic pancreatic cancer in the duodenum is a very rare disease. Only twelve cases have been reported worldwide to date. We report a rare case of malignant transformation of heterotopic pancreas (Heinrich type III) in the duodenum with long-term survival of the patient, and review the 12 cases in the literature.Case presentationA 75-year-old Japanese man was admitted to our hospital complaining of nausea and vomiting. Endoscopy and upper gastrointestinal contrast study showed marked duodenal stenosis. A pylorus-preserving pancreaticoduodenectomy was performed. Histopathological examination of the surgically resected specimen showed malignant transformation of heterotopic pancreas (Heinrich type III) in the duodenum. The postoperative course was uneventful, and the patient was discharged from the hospital on postoperative day 30. He is well and shows no signs of recurrence at the time of writing, six years after the surgery.ConclusionAdenocarcinoma arising within the heterotopic pancreas appears to be rare. It is difficult to obtain a correct diagnosis preoperatively. The management of heterotopic pancreas depends on the presence or absence of symptoms. If the patient is asymptomatic or benign, conservative treatment with regular follow-up is recommended. When the patient is symptomatic or there is a suspicion of malignancy, surgical management with intra-operative frozen section diagnosis is indicated.

Predictors of lymph node metastasis in T1 colorectal carcinoma: an immunophenotypic analysis of 265 patients.

BACKGROUND: The appropriateness of endoscopic resection in patients with T1 colorectal carcinomas is unclear. Highly precise predictors of lymph node metastasis are required to optimize the outcomes of treatments for T1 colorectal carcinomas. OBJECTIVE: The purpose of this work was to identify predictors of lymph node metastasis by examining the clinicopathologic significance of immunophenotypes found in T1 colorectal carcinomas. DESIGN: This was a retrospective study. SETTINGS: The study was conducted at a university hospital. PATIENTS: Included were 265 patients with T1 colorectal carcinoma who underwent radical surgery. INTERVENTIONS: Patients with T1 colorectal carcinoma were managed. MAIN OUTCOME MEASURES: Immunophenotypes were associated with various clinicopathologic parameters, and CD10 expression was strongly associated with lymph node metastasis. RESULTS: The levels of MUC2, MUC5AC, and CD10 expression were individually significantly associated with tumor location, growth pattern, histologic type, invasive potential, and metastatic potential. The incidence of lymph node metastasis was significantly associated with each of the 5 following parameters: depth of submucosal invasion (p = 0.005), tumor budding (p < 0.001), lymphatic invasion (p < 0.001), MUC2 expression (p = 0.006), and CD10 expression (p < 0.001). Multivariate analysis showed that CD10 expression (OR, 9.2 [95% CI, 2.5–39.8]; p = 0.001) and lymphatic invasion (OR, 6.3 [95% CI, 2.5–17.7]; p < 0.001) were independently associated with lymph node metastasis. LIMITATIONS: This study was limited by its small sample size, intraobserver variation attributed to immunohistochemical staining, and potential selection bias because surgically resected specimens were collected instead of endoscopically resected specimens. CONCLUSIONS: We suggest that CD10 expression is closely associated with lymph node metastasis in T1 colorectal carcinoma.

Clinical study on the pathophysiology and treatment of PPI-resistant ulcers

We studied the gastric acidity, gastric emptying, and proton pump inhibitor (PPI) plasma levels in 10 patients with PPI-resistant ulcers. The pH 3 holding-time ratio was low in nine of these patients, with an average ratio of only 39%. PPI plasma levels in those patients were also much lower than in those with nonresistant ulcers. Gastric emptying, determined by the acetaminophen method, was reduced in all 10 patients. Therefore, PPI-resistant ulcers appear to result from insufficient inhibition of gastric acidity, with reduced gastric emptying interfering with the absorption of PPIs. In patients with mild reductions in gastric emptying, PPI plasma levels increased after a change from single-unit enteric-coated tablets (omeprazole) to multiunit enteric-coated granules in capsules (lansoprazole). This change in formulation markedly inhibited gastric acidity and led to rapid healing. In patients with moderate reductions in gastric emptying, doubling the dose of lansoprazole was effective. In patients with severely reduced gastric emptying, there appeared to be a limit to the effectiveness of oral administration of PPIs. Changing the formulation and doubling the dose to compensate for reduced gastric emptying are effective approaches in the treatment of patients with PPI-resistant ulcers.

Pathological factors related to lymph node metastasis of submucosally invasive gastric cancer: criteria for additional gastrectomy after endoscopic resection

BackgroundThere are currently no universally accepted indications and criteria for additional gastrectomy after endoscopic resection of submucosally invasive cancer. The purpose of the present study was to establish accurate indications and criteria for such additional gastrectomy on the basis of lymph node metastasis risk.MethodsWe investigated 130 submucosally invasive gastric cancers and analyzed the pathological risk factors for lymph node metastasis. The tumors were evaluated for pathological factors in the area of invasion, and factors were compared between the cases with lymph node metastasis and those without.ResultsUnivariate logistic regression analysis showed that tumor minor axis length, depth of invasion, histological classification of the area of submucosal invasion, absence of lymphoid infiltration, ulceration or scar in the lesion, and lymphatic and venous invasion are statistically significant risk factors for lymph node metastasis. Multivariate logistic regression analysis showed that the absence of lymphoid infiltration and the presence of lymphatic invasion are statistically significant as risk factors for lymph node metastasis.ConclusionsWe present a scoring system on the basis of the pathological criteria tested in this study. Our findings enable more accurate identification of patients who should undergo additional gastrectomy after endoscopic resection.

Surgical treatment for abdominal actinomycosis: A report of two cases

Since actinomycosis sometimes causes an abdominal tumor which mimics malignancy, treatment strategy varies from case to case. We herein report two cases which were treated with a combination of antibiotics and surgical intervention. Both patients presented with an intra-abdominal tumor lesion mimicking malignant disease after an appendectomy for acute appendicitis. Case 1 received surgical extirpation of the abdominal tumor in the liver and kidney twice since the clinical diagnosis of actinomycosis was not made. In contrast, case 2 was successfully treated by a combination of antibiotics and laparoscopic surgery following the experience of case 1. When a high probability diagnosis can be made, a laparoscopic approach is a useful and effective option to treat this condition.

Primary CD56+ NK/T-cell lymphoma of the rectum accompanied with refractory ulcerative colitis.

A case of primary NK/T-cell lymphoma of the rectum accompanied with ulcerative colitis (UC) in a 73-year-old man is reported. He had a 6-year history of repeated admission to our hospital for UC. Total colonoscopy performed 4 months after resolution of refractory UC complicated by cytomegalovirus colitis showed a markedly submucosal tumor in the rectum, which was histologically diagnosed as malignant lymphoma. The findings of computed tomography of the chest and abdomen, gallium scintigraphy, abdominal ultrasonography, and upper gastrointestinal endoscopy showed no abnormal lesions. Therefore, based on a diagnosis of localized rectal lymphoma with UC, proctocolectomy was performed. The resected specimen showed three submucosal tumors in the rectum with local nodal involvement. Histologically, the tumors were characterized by diffusely infiltrating sheets of large atypical lymphoid cells, which were negative for CD4, CD8, and CD20 but were positive for CD56, CD3, and granzyme B. The presence of Epstein-Barr virus (EBV) infection in neoplastic cells was shown by in situ hybridization for EBV-encoded early small RNA1 (EBER-1). Based on these findings, the patient was diagnosed with primary CD56+ NK/T-cell lymphoma of the rectum (stage IIE). This is the first case report of primary rectal NK/T-cell lymphoma accompanied with UC.