Efficacy of Endobiliary Radiofrequency Ablation using a Novel Endoluminal Radiofrequency Ablation Catheter in a Swine Model.

Purpose: Endobiliary radiofrequency ablation (RFA) is a new endoscopic ablative technique. However, the ideal power setting for RFA has not yet been clarified. Therefore, we intended to evaluate the effects of endobiliary RFA according to time variations using novel RFA. Materials and methods: Nine female pigs were divided into three groups according to ablation time (60, 90, and 120 seconds) with the same setting (10 watts, 80 °C). All pigs underwent endoscopic retrograde cholangiography (ERC) and endobiliary RFA in the common bile duct. Gross and histologic examinations were performed after 24 hours. Results: The ERC and application of the endobiliary RFA were 100% successful, and the post-RFA cholangiogram did not show contrast leakage. The median depth of microscopic ablation was significantly different among the three groups (60 vs. 90 vs. 120 seconds = 1.90 (1.17-2.23) vs. 2.44 (2.31-2.60) vs. 2.52 (2.47-2.64) mm, p = 0.018). There was also a linear relationship between ablation time and microscopic ablation depth (r2 = 0.552, p = 0.002). However, no significant differences in macroscopic or microscopic ablation length were observed. In addition, there were focal ablation injuries in adjacent liver tissue in five of the nine pigs (2/3 in 60, 1/3 in 90, and 2/3 in 120 seconds). Conclusion: Endobiliary RFA using a novel RFA catheter resulted in controlled ablation with a linear relationship between microscopic ablation depth and ablation time in a swine model. Clinical studies are needed to validate the safe energy condition of endobiliary RFA in malignant biliary obstruction.

Factors to improve the interobserver agreement for gastric atrophy and intestinal metaplasia: consensus of definition and criteria.

AIMS: Intestinal metaplasia and atrophy of the gastric mucosa are associated with Helicobacter pylori infection and are considered premalignant lesions. The updated Sydney system is used for these parameters, but experienced pathologists and consensus processes are required for interobserver agreement. We sought to determine the influence of the consensus process on the assessment of intestinal metaplasia and atrophy. METHODS AND RESULTS: Two study sets were used: consensus and validation. The consensus set was circulated and five gastrointestinal pathologists evaluated them independently using the updated Sydney system. The consensus of the definitions was then determined at the first consensus meeting. The same set was recirculated to determine the effect of the consensus. The second consensus meeting was held to standardise the grading criteria and the validation set was circulated to determine the influence. Two additional circulations were performed to assess the maintainance of consensus and intraobserver variability. Interobserver agreement of intestinal metaplasia and atrophy was improved through the consensus process (intestinal metaplasia: baseline κ = 0.52 versus final κ = 0.68, P = 0.006; atrophy: baseline κ = 0.19 versus final κ = 0.43, P < 0.001). Higher interobserver agreement in atrophy was observed after consensus regarding the definition (pre-consensus: κ = 0.19 versus post-consensus: κ = 0.34, P = 0.001). There was improved interobserver agreement in intestinal metaplasia after standardisation of the grading criteria (pre-standardisation: κ = 0.56 versus post-standardisation: κ = 0.71, P = 0.010). CONCLUSIONS: This study suggests that interobserver variability regarding intestinal metaplasia and atrophy may result from lack of a precise definition and fine criteria, and can be reduced by consensus of definition and standardisation of grading criteria.

Clinicopathological Characteristics of Serrated Polyposis Syndrome in Korea: Single Center Experience.

Background/Aim. Serrated polyposis syndrome (SPS) is a rare condition characterized by multiple serrated polyps throughout the colon and rectum. The aim of this study was to evaluate the clinicopathological characteristics of SPS in Koreans. Methods. This retrospective analysis of prospectively collected data was performed using information from the endoscopy, clinical records, and pathology database system of Uijeongbu St. Mary's Hospital. Consecutive patients satisfying the updated 2010 World Health Organization criteria for SPS between June 2011 and May 2014 were enrolled. Results. Of the 17,552 patients who underwent colonoscopies during the study period, 11 (0.06%) met the criteria for SPS. The mean age of these patients was 55.6 years. Ten patients (91%) were males. None had a family history of CRC or a first-degree relative with SPS. Seven patients (64%) had synchronous advanced adenoma. One patient had coexistence of SPS with CRC that was diagnosed at the initial colonoscopy. Five patients (45%) had more than 30 serrated polyps. One of the patients underwent surgery and 10 underwent endoscopic resection. Conclusion. The prevalence of SPS in this study cohort was comparable to that in Western populations. Considering the high risk of CRC, correct diagnosis and careful follow-up for SPS are necessary.

C-Kit-Negative Gastrointestinal Stromal Tumor in the Stomach.

C-kit-negative gastrointestinal stromal tumors (GISTs) are uncommon, and there have been few reports about the diagnosis and treatment of c-kit-negative GISTs in the stomach. We report the case of a patient who was diagnosed with a huge and atypical GIST in the stomach. The GIST was completely resected and finally diagnosed as c-kit-negative GIST based on immunohistochemical staining of tumor cells, which were negative for CD117 and CD34 and positive for Discovered on GIST-1 (DOG1). C-kit-negative GISTs could be treated by complete resection and/or imatinib, which is the same treatment for c-kit-positive GISTs.

Resistance to erythropoiesis-stimulating agents is associated with arterial microcalcification in early hemodialysis patients.

The aim of this study was to evaluate the relationship between arterial microcalcification (AMiC) and erythropoiesis-stimulating agents (ESA) hyporesponsiveness in hemodialysis patients. The presence of AMiC was confirmed by pathologic examination of von Kossa-stained arterial specimens acquired during vascular access surgery. We assessed the ESA hyporesponsiveness index (EHRI), defined as the weekly ESA dose per kilogram body weight divided by the hemoglobin level. AMiC was detected in 33 (40.2%) of 82 patients. Patients with diabetes had a higher incidence of AMiC than patients without diabetes. The serum levels of albumin and cholesterol were higher in patients without AMiC than in patients with AMiC. The serum levels of intact parathyroid hormone were lower in patients with AMiC than in patients without AMiC. The serum levels of phosphate and calcium-phosphorus product did not differ between the two groups. The mean EHRI value was higher in patients with AMiC than in patients without AMiC. In multivariate analyses, ESA hyporesponsiveness and diabetes showed a significant association with AMiC. In conclusion, ESA hyporesponsiveness may be a clinical relevant parameters related to AMiC in hemodialysis patients.

Arterial micro-calcification of vascular access is associated with aortic arch calcification and arterial stiffness in hemodialysis patients.

Vascular calcification of the coronary arteries or aorta is an independent risk factor for cardiovascular outcome, but clinical significance of arterial micro-calcification (AMC) of vascular access is unclear in hemodialysis (HD) patients. Sixty-five patients awaiting vascular access operation were enrolled. We compared surrogate markers of cardiovascular morbidity such as aortic arch calcification (AoAC) by chest radiography, arterial stiffness by brachial-ankle pulse wave velocity (baPWV) and endothelial dysfunction by flow-mediated dilatation (FMD) between patients with and without AMC of vascular access on von Kossa staining. AMC of vascular access was detected in 36 (55.4%). The AMC-positive group had significantly higher incidence of AoAC (63.9% vs. 20.7%, p < 0.001) and higher baPWV (26.5 ± 9.4 m/s vs. 19.8 ± 6.6 m/s, p = 0.006) than the AMC-negative group. There was no significant difference in FMD between the two groups (5.4 ± 2.6% vs. 5.7 ± 3.5%, p = 0.764). The AMC-positive group had higher incidence of diabetes mellitus, higher systolic blood pressure and wider pulse pressure than the AMC-negative group. This study suggests that AMC of vascular access may be associated with cardiovascular morbidity via AoAC and arterial stiffness in HD patients.

Current trends in the epidemiological and pathological characteristics of gastrointestinal stromal tumors in Korea, 2003-2004.

Despite remarkable progress in understanding and treating gastrointestinal stromal tumors (GISTs) during the past two decades, the pathological characteristics of GISTs have not been made clear yet. Furthermore, concrete diagnostic criteria of malignant GISTs are still uncertain. We collected pathology reports of 1,227 GISTs from 38 hospitals in Korea between 2003 and 2004 and evaluated the efficacy of the NIH and AFIP classification schemes as well as the prognostic factors among pathologic findings. The incidence of GISTs in Korea is about 1.6 to 2.2 patients per 100,000. Extra-gastrointestinal GISTs (10.1%) are more common in Korea than in Western countries. In univariate analysis, gender, age, tumor location, size, mitosis, tumor necrosis, vascular and mucosal invasions, histologic type, CD34 and s-100 protein expression, and classifications by the NIH and AFIP criteria were found to be significantly correlated with patient's survival. However, the primary tumor location, stage and classification of the AFIP criteria were prognostically significant in predicting patient's survival in multivariate analysis. The GIST classification based on original tumor location, size, and mitosis is more efficient than the NIH criteria in predicting patient's survival, but the mechanism still needs to be clarified through future studies.

Inflammatory pseudotumor in the middle ear cavity.

Inflammatory pseudotumor includes a diverse group of lesions characterized by inflammatory cell infiltration and variable fibrotic responses. It is extremely rare in the middle ear alone. A 7-year-old girl presented right hearing impairment. Because an otitis media with effusion was first suspected, a myringotomy was performed, but it found a mass that was different from a congenital cholesteatoma. Canal wall-down tympanomastoidectomy removed the mass successfully. The pathologic study of the specimen confirmed an inflammatory pseudotumor. We report an extremely rare case of the inflammatory pseudotumor in the middle ear with a review of the poor literature about this subject.

Ruptured epidermal inclusion cysts in the subareolar area: sonographic findings in two cases.

Epidermal inclusion cyst of the breast is an uncommon benign lesion and it is usually located in the skin layer. We report here on two cases of ruptured epidermal inclusion cysts in the subareolar area, which is a very unusual location for these cysts and these lesions can be mistaken for breast malignancies.

Hyalinizing spindle cell tumor with giant rosettes with pulmonary metastasis after a long hiatus: a case report.

Hyalinizing spindle cell tumor with giant rosettes (HSCTGR) is a recently described tumor, which is regarded as an unusual variant of low-grade fibromyxoid sarcoma. Proof of a metastatic potential was lacking. The patient in the report was a 35-yr-old woman who showed multiple bilateral pulmonary nodules with massive pleural effusion in the right side. She had a history of a mass excision in the right thigh 11 yrs ago at another hospital, which was reported as a "leiomyoma". Two years before this presentation, the patient received a routine chest radiograph which demonstrated bilateral multiple pulmonary nodules. A lobectomy of the left upper lung was performed. The histological findings revealed a well-circumscribed nodule that was characterized by a spindle-shaped fibrous to hyalinized stroma with criss-crossing short fascicles and giant collagen rosettes surrounded by a rim of spindle-shaped cells. Electron microscopy confirmed the fibroblastic nature of the tumor. This case, in addition to at least two other cases reported in the literature, demonstrates that the HSCTGR is a malignant neoplasm with the capacity to metastasize after a long hiatus.

HER-2/neu oncogene amplification by chromogenic in situ hybridization in 130 breast cancers using tissue microarray and clinical follow-up studies.

Determining of HER-2/neu oncogene amplification has become clinically important for managing breast cancer. Fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) are currently regarded as the standard methods. Chromogenic in situ hybridization (CISH) was investigated as a new modification with an accurate, sensitive technique. From 1998 to 2002, using CISH and IHC, the amplification and protein expression of the HER-2/neu oncogene were examined using paraffin sections in 130 breast carcinomas and to determine the prognostic role of HER-2/neu for outcome after a follow-up of 24- 64 months. Amplifications by CISH and overexpression by IHC were observed in 28 (22%) and 27 cases (20.8%), respectively. Of the 104 patients, 20 patients (19.2%) with amplification had a shorter disease-free interval (34.9 months vs. 38.0 months in controls) (p=0.372). 15 patients (14.4%) had a disease recurrence, but there is no significant difference between 3 patients amplifying the oncogene and 12 patients without oncogene (20.6 months vs. 19.6 months) (p=0.862). 6 patients (5.8%) of these died. CISH is a useful alternative, particularly for confirming the IHC results. There is no relationship between the early recurrence and the HER-2/neu positive group, but lymph node status was statistically significant.