MRI Findings and Differential Diagnosis of Anterior Mediastinal Solid Tumors.

The anterior mediastinum is the most common location of mediastinal tumors, and thymic epithelial tumors are the most common mediastinal tumors. It is important to differentiate thymic epithelial tumors from malignant lymphomas and malignant germ cell tumors because of the different treatment strategies. Dynamic contrast-enhanced MRI and diffusion-weighted imaging can provide additional information on the differential diagnosis. Chemical shift imaging can detect tiny fat tissues in the lesion and is useful in differentiating thymic hyperplasia from other solid tumors such as thymomas. MRI findings reflect histopathological features of mediastinal tumors, and a comprehensive evaluation of MRI sequences is important for estimation of the histopathological features of the tumor. In this manuscript, we describe the MRI findings of anterior mediastinal solid tumors and the role of MRI in the differential diagnosis.

Anterior mediastinal lesions: CT and MRI features and differential diagnosis.

Anterior mediastinum is the most common location of mediastinal tumors, which include various solid and cystic lesions. The lesion location and CT and MRI features are important in the differential diagnosis. Recently, CT-based mediastinal compartment classification systems were proposed and suggested to be useful for accurate evaluation of mediastinal lesions. CT and MRI reflect the pathological findings of mediastinal lesions, and knowledge of the pathological features is important for the differential diagnosis. In this article, we review the CT and MRI features of anterior mediastinal lesions and describe important points in the differential diagnosis.

CT-based mediastinal compartment classifications and differential diagnosis of mediastinal tumors.

Division of the mediastinum into compartments is used to help narrow down the differential diagnosis of mediastinal tumors, assess tumor growth, and plan biopsies and surgical procedures. There are several traditional mediastinal compartment classification systems based upon anatomical landmarks and lateral chest radiograph. Recently, the Japanese Association of Research of the Thymus (JART) and the International Thymic Malignancy Interest Group (ITMIG) proposed new mediastinal compartment classification systems based on transverse CT images. These CT-based classification systems are useful for more consistent and exact diagnosis of mediastinal tumors. In this article, we review these CT-based mediastinal compartment classifications in relation to the differential diagnosis of mediastinal tumors.

Increase in Endoscopic and Laparoscopic Surgery Regarding the Therapeutic Approach of Gastric Cancer Detected by Cancer Screening in Saga Prefecture, Japan.

Objective Despite recent advances in endoscopic treatment and laparoscopic surgery for gastric cancers, an increase in the uptake of these therapeutic approaches has not yet been fully demonstrated. Therefore, the present study aimed to investigate the change in therapeutic approaches regarding the treatment of gastric cancers detected by cancer screening in Saga Prefecture, Japan between April 2002 and March 2011. Methods Gastric cancer screening by X-ray was performed on 311,074 subjects between April 2002 and March 2011. In total, 534 patients were thereafter diagnosed with gastric cancer. Eighteen subjects were excluded because precise details of their treatment were not available. To evaluate the changes in the therapeutic approach, the observation period was divided into three 3-year intervals: Period I: April 2002 to March 2005; Period II: April 2005 to March 2008; Period III: April 2008 to March 2011. Results The use of open laparotomy for the treatment of gastric cancer decreased, and laparoscopic surgery and endoscopic treatment increased markedly in a time-dependent manner. A 2.5-fold increase in endoscopic treatment, and a 18.4-fold increase in laparoscopic surgery were observed in Period III compared with Period I (after adjusting for age and tumor characteristics). Conclusion Endoscopic treatment and laparoscopic surgery for gastric cancer increased during the investigation period (2002-2011), although the tumor characteristics of the gastric cancers detected through cancer screening in Saga Prefecture, Japan did not show any changes.

Repeated screening with fecal immunochemical tests reduced the incidence of colorectal cancers in Saga, Japan.

BACKGROUND/AIMS: Screening with fecal occult blood test has reduced mortality from colorectal cancer (CRC), with fecal immunochemical tests (FIT) widely utilized for CRC screening in Japan. To evaluate the importance of repeated FIT screening, the incidence of CRC was compared in patients undergoing initial and repeated screening. METHODOLOGY: Participants aged ≥40 years in Saga, Japan, were invited to undergo a 2-day FIT. FIT positive subjects were verified by colonoscopy to evaluate the CRC incidence rates. RESULTS: From 2005 to 2007, 55,595 individuals were invited to undergo CRC screening, including 47,168 undergoing repeated and 8,427 undergoing initial screening. Of the 5,832 FIT-positive subjects, 4,615 were assessed by colonoscopy, with 114 diagnosed as having CRC. Of these 114 patients, 67 had early and 47 had advanced CRC. The risk of CRC was 63% lower in the repeated than in the initial screening group (p<0.0001). Of the 67 patients with early CRC, 42 underwent endoscopic resection, with the rate significantly higher in the repeated than in the initial screening group (p = 0.01). Overall survival was longer in screened subjects than in those who visited hospitals with clinical symptoms. CONCLUSIONS: Repeated CRC screening with FIT reduced the incidence of CRC in Saga, Japan.

CT-gastrography for early gastric cancer visualized by wall-carving technique using contrast-enhanced MDCT for portal phase.

OBJECTIVE: The wall-carving (WC) imaging technique is used to evaluate early gastric cancer using multidetector row computed tomography (MDCT) image data for only the arterial phase. Our purpose was to investigate if WC images derived from portal phase MDCT images can enhance the visualization of early gastric cancer. SUBJECTS AND METHODS: Fourteen consecutive patients (average age/age range (years) = 75.8/61 to 86; male/female = 9/5) were enrolled. They were diagnosed with early gastric cancer and underwent contrast-enhanced MDCT before treatment. WC images of the arterial and portal phases were created from images scanned by 64-detector-row MDCT 40 and 60 seconds after the initiation of the contrast material injection, respectively. The correlation between the detection rates of lesions in the WC images and pathological findings was investigated. RESULTS: Totals of 71.4% (10/14) of arterial phase WC images and 71.4% (10/14) of portal phase WC images showed lesions. The imaging ability improved to 85.7% (12/14) when the two sets of images were combined. Well-differentiated adenocarcinomas tended to be visualized better in WC images of any phases. CONCLUSION: WC is an excellent image analysis technique for visualizing early gastric cancer lesions. The depiction rates were improved by using a combination of arterial and portal WC images. The scan timing after the contrast material injection should be carefully investigated to improve the detection rate of lesions.

Aneurismal type of colorectal cancer: imaging characteristics of gastrointestinal endoscopy, computed tomography and magnetic resonance imaging.

BACKGROUND/AIMS: Only a few studies have investigated aneurismal large-intestinal malignant diseases. The present study reported five cases of aneurismal colon cancer that were experienced over 20 years. The present study aims to define the pathological and diagnostic imaging characteristics of aneurismal colon cancer. METHODOLOGY: A case series from a retrospective review of large-intestinal malignant tumors at Saga Medical School, Japan. Barium enema was performed in 876 patients with large-intestinal advanced cancer, which included five with aneurismal-type cancer. RESULTS: The characteristics of the 5 cases were as follows: (i) pathological findings were poorly differentiated adenocarcinoma without desmoplastic change or mucinous adenocarcinoma; (ii) a typical aneurismal type revealed by barium enema had a low elevated tumor edge without stenosis upon endoscopic examination; (iii) computed tomography showed low attenuation without enhancement of contrast material; and (iv) magnetic resonance imaging indicated high intensity in the T2-weighted images of mucinous adenocarcinoma. CONCLUSION: We revealed 5 cases of aneurismal colon cancer, which had characteristic pathological findings and diagnostic imaging, and poor prognosis.

Bleeding and stenosis caused by reflux esophagitis was not common in emergency endoscopic examinations: a retrospective patient chart review at a single institution in Japan.

BACKGROUND: Bleeding and stenosis are serious complications of reflux esophagitis, although few studies have been performed in Japan regarding these complications. This study aimed to indicate the characteristics of reflux esophagitis observed during emergency endoscopic examination in Japan. METHODS: All subjects who had emergency endoscopic examination performed between 1990 and 2004 at Saga Medical School Hospital were evaluated. Patients with endoscopic reflux esophagitis were evaluated with a retrospective patient chart review. RESULTS: A total of 1621 subjects underwent emergency endoscopy; 1420 of the endoscopies were because of hematemesis or melena. Endoscopic examination revealed that 19 cases with bleeding were caused by reflux esophagitis (19/1621, 1.2%). The 19 patients with bleeding and the four patients with stenosis (0.2%) had emergency endoscopy performed for complications of reflux esophagitis. The Los Angeles classification of these 23 cases showed that most were severe esophagitis (grade A, 0; B, 2; C, 8; and D, 13). The frequency of comorbidity with diabetes mellitus and collagen disease and the proportion of heavy drinkers were higher in patients who received emergency endoscopy because of reflux esophagitis than in those diagnosed with reflux esophagitis but who received emergency endoscopy because of other diseases. CONCLUSIONS: Relatively small numbers of patients with reflux esophagitis undergo emergency endoscopy in Japan, and most such patients have underlying diseases, including diabetes mellitus and collagen disease. This finding is supported by a previous report that severe esophagitis is not common in Japan.

Endoscopic hemostasis for bleeding gastric varices treated by combination of variceal ligation and sclerotherapy with N-butyl-2-cyanoacrylate.

BACKGROUND: Bleeding from esophagogastric varices is a serious complication of portal hypertension. The aim of the present study was to determine whether endoscopic sclerotherapy with injection of N-butyl-2-cyanoacrylate combined with variceal ligation was useful for hemostasis of bleeding gastric varices. METHODS: Twenty-seven patients with bleeding gastric varices underwent endoscopic treatment with variceal ligation followed by sclerotherapy with N-butyl-2-cyanoacrylate from November 1995 to November 2000. Patients underwent endoscopic variceal ligation only for the bleeding spot just before sclerotherapy. Injection was continued until varices were engorged. After these therapies, patients were followed for at least for 5 years. Retreatment was applied as necessary. RESULTS: Among these patients, 11 had active bleeding and 16 had recent bleeding within 24 h with white or red plaques on gastric varices. All varices presented as nodular or tumorous forms. The hemostasis rate at 1 week after treatment with N-butyl-2-cyanoacrylate was 88.9% (24/27). Among the patients achieving hemostasis at 1 week, 33.3% (8/24) experienced recurrent bleeding between 5 and 53 months after the initial treatment. Five patients with rebleeding were treated with N-butyl-2-cyanoacrylate, and the other three patients were treated by other procedures. The final hemostasis rate was 81.5% (22/27). The 5-year survival rate after initial hemostasis was 63.0% (17/27). CONCLUSIONS: This study showed that endoscopic variceal ligation combined with sclerotherapy might become a recommended choice for effective treatment of bleeding gastric varices.

[A case of relapsed ischemic colitis with colon cast-like stripped mucosa].

An 82-year-old woman who had 5 relapses of ischemic colitis was admitted with sudden lower abdominal pain. Colonoscopic examination performed on the 2nd day revealed colon cast-like stripped colonic mucosa in the lower portion of the descending colon. She was treated conservatively. After 2 weeks, ischemic colitis healed, with slight residual stenosis. Most reports of colon cast indicated that colon cast was caused by abdominal aneurysm, operation, or external wound. The only predisposing conditions in this case were arteriosclerosis of abdominal aorta and chronic constipation. Arteriosclerosis and chronic constipation might be the important risk factors of ischemic colitis with colon cast and relapsing of ischemic colitis.

A pilot randomized control study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors.

AIM: Rectal carcinoid tumors smaller than 10 mm can be resected with local excision using endoscopy. In order to remove rectal carcinoid tumors completely, we evaluated endoscopic mucosal resection with a ligation device in this pilot control randomized study. METHODS: Fifteen patients were diagnosed with rectal carcinoid tumor (less than 10 mm) in our hospital from 1993 to 2002. There were 9 males and 6 females, with a mean age 61.5 years (range, 34-77 years). The patients had no complaints of carcinoid syndrome symptoms. Fifteen patients were randomly divided into 2 groups: 7 carcinoid tumors were treated by conventional endoscopic resection, and 8 carcinoid tumors were treated by endoscopic resection using a ligation device. RESULTS: All rectal carcinoid tumors were located at the middle to distal rectum. The size of the tumors varied from 3 mm to 10 mm and background characteristics of the patients were not different in the two groups. The rate of complete removal of carcinoid tumors using a ligation device (100%, 8/8) was significantly higher than that of conventional endoscopic resection (57.1%, 4/7). The three patients had tumor involvement of deep margin, for which additional treatment was performed. No complications occurred during or after endoscopic resection using a ligation device. All patients in the both groups were alive during the 3-year observation period. CONCLUSION: Endoscopic resection using a ligation device is a useful and safe method for resection of small rectal carcinoid tumors.

Oral dimethyl sulfoxide for systemic amyloid A amyloidosis complication in chronic inflammatory disease: a retrospective patient chart review.

BACKGROUND: Amyloid A amyloidosis is an obstinate disease complication in chronic inflammatory disease, and there are few effective therapies. The objective of this study was to investigate the effect of oral dimethyl sulfoxide (DMSO) on amyloid A amyloidosis. METHODS: Fifteen secondary amyloid A amyloidosis patients (4 men, 11 women; age, 23-70 years) were treated with DMSO between 1995 and 2003. DMSO was administered orally in all patients at a dose of 3-20 g/day. The clinical symptoms together with the renal and gastrointestinal functions were evaluated before and after treatment. RESULTS: Among the 15 patients, amyloid A amyloidosis was a complication of rheumatoid arthritis (RA) in 10, of Crohn's disease in 4, and of Adult Still's disease in 1. Nine cases mainly involved the kidney, with renal dysfunction and proteinuria, five mainly involved the gastrointestinal tract, with protein-losing gastroenteropathy and intractable diarrhea, and one involved both gastrointestinal and renal amyloidosis. DMSO treatment was successful in 10 (66.7%) of the 15 patients (RA, 6/10; Crohn's disease, 4/4; Adult Still's disease, 0/1). Eight weeks of DMSO administration improved the renal function and proteinuria in five out of ten renal amyloidosis patients, but had no effect on those patients with severe and/or advanced renal dysfunction. With regard to gastrointestinal amyloidosis, gastrointestinal symptoms, including diarrhea and protein-losing gastroenteropathy, were improved in six patients. No serious side effects were encountered with the DMSO treatment. CONCLUSIONS: Oral administration of DMSO is an effective treatment for amyloid A amyloidosis, especially for gastrointestinal involvement and the early stage of renal dysfunction.

Clinical outcomes of EMR for gastric tumors: historical pilot evaluation between endoscopic submucosal dissection and conventional mucosal resection.

BACKGROUND: EMR is currently a standard treatment for mucosal gastric tumors. Endoscopic submucosal dissection (ESD) has been developed for en bloc resection. OBJECTIVE: We evaluated the clinical outcomes of ESD compared with conventional EMR. DESIGN: Not applicable. SETTING: A historical control study was performed between EMR and ESD. PATIENTS: EMR of 245 gastric tumors was performed in 229 patients. Lesions were divided into two groups. Conventional EMR was performed in group A from February 1999 to June 2001, and ESD was performed in group B from July 2001 to March 2004. Group B was divided into subgroups: subgroup B-1 underwent ESD from July 2001 to March 2003 and subgroup B-2 from April 2003 to March 2004. INTERVENTIONS: All lesions were resected with conventional EMR or with ESD. MAIN OUTCOME MEASUREMENTS: En bloc resection rate, rate in completeness of resection, required time, remnant ratio, and complications were evaluated. RESULTS: With regard to lesions >10 mm in size, the en bloc resection rate and the rate in completeness of resection of group B was significantly higher than that of group A (p < 0.01). Although the required time was longer in group B than A (p < 0.01), it was shorter in subgroup B-2 compared with B-1 (p < 0.05) with lesions < or =10 mm in size. The remnant ratio and perforation rate were not different between groups. LIMITATIONS: Not applicable. CONCLUSIONS: The en bloc resection rate was better with ESD than with conventional EMR. The required time was longer in ESD, but this disadvantage might be improved with experience.