Thomas G. Morales

The difference in colon polyp size before and after removal

BACKGROUND Accurate knowledge of polyp size is important in assessing cancer risk in both clinical studies and individual patients. We sought to determine if a difference exists between the endoscopic estimation of colon polyp size and the actual measurement after removal. METHODS We measured polyps in a systematic fashion. Using open biopsy forceps as a guide, the largest diameter of 31 pedunculated polyps was estimated endoscopically. The polyp was then removed by snare polypectomy and directly measured by a technician who was blinded to the endoscopic estimate. Each polyp was also measured after formalin fixation by a pathologist who was blinded to previous measurements. RESULTS There was a significant difference between the endoscopic estimates and the postpolypectomy measurements. Endoscopic estimates on average were 1.6 mm greater than the postpolypectomy measurements (p< 0.05), representing an 18% difference. Twenty-three of the 31 (74%) endoscopic estimates were larger than the postpolypectomy measurements. There was not a significant difference between the postpolypectomy and postfixation measurements. CONCLUSIONS The size of polyps measured endoscopically is significantly larger on average than postpolypectomy measurements. This is most likely due to factors involved in the removal of the in vivo polyp.

Long-term follow-up of intestinal metaplasia of the gastric cardia

OBJECTIVE:Recent studies have found a relatively high prevalence of gastric cardia intestinal metaplasia in individuals presenting for elective upper endoscopy. It has been hypothesized that this lesion may be a precursor of gastric cardia cancer. Our objective was to identify the incidence of dysplasia in patients with gastric cardia intestinal metaplasia.METHODS:Twenty-eight patients who had previously been identified with cardia intestinal metaplasia had follow-up examinations performed. None of the patients had dysplasia at the time of diagnosis. All had an examination at 1 yr, and 20 patients had an examination at 3 yr after diagnosis. During follow-up examinations all patients underwent vital staining with methylene blue to help identify areas of intestinal metaplasia in the cardia. Two to four biopsies were taken from blue-stained mucosa. Histological specimens were stained using a combination of hematoxylin and eosin with Alcian blue at pH 2.5.RESULTS:There were 27 men and one woman with a mean age of 69.8 yr (range, 48–83 yr). The mean length of follow-up was 2.5 yr (range, 12–46 months). Only one patient was diagnosed with dysplasia (low-grade) during the study, for an incidence of 1.4% per yr.CONCLUSIONS:The prevalence (0%) and incidence (1.4%/yr) of dysplasia in cardia intestinal metaplasia are low. Although further studies are needed, screening and surveillance for gastric cardia intestinal metaplasia is unlikely to be clinically useful for the prevention of gastric cardia cancer.

Adenocarcinoma of the Gastric Cardia

Although adenocarcinoma of the stomach has decreased in incidence over the past several decades, cancer of the gastric cardia has increased rapidly over this time frame. There are several differences between adenocarcinoma of the cardia and distal stomach with respect to epidemiology, risk factors, and prognosis. In addition, recent data raise questions with regard to possible associations of cardia cancer with Barretts esophagus, intestinal metaplasia of the cardia, and Helicobacter pylori. This article will review the current literature with regard to this important tumor and explore these potential disease associations.

Inability to Noninvasively Diagnose Gastric Intestinal Metaplasia in Hispanics or Reverse the Lesion with helicobacter pylori Eradication

Background Helicobacter pylori infection has been linked with the development of gastric adenocarcinoma and its precursor lesion, intestinal metaplasia (IM). The presence of gastric IM is not associated with symptoms, which makes identification of individuals with this lesion difficult. It is not clear whether eradication of H. pylori infection leads to reversal of gastric IM or the potential decrease in the risk of cancer in these patients. Goals The purpose of this pilot study was to define the prevalence of gastric IM in a population at high risk for gastric cancer (Southwestern Hispanics), examine the ability of noninvasive testing to identify individuals with the lesion, and determine whether eradication of H. pylori infection reverses gastric IM in this population. Study Subjects from the Tucson metropolitan area were recruited, and baseline data, including the presence of upper gastrointestinal (UGI) symptoms, urinary sodium, and serum pepsinogen levels, were obtained. Upper endoscopy was performed and six gastric biopsies from specific anatomic sites were obtained, followed by methylene blue staining with targeted biopsies from blue-stained mucosa. Biopsies were evaluated for the presence of H. pylori infection and gastric IM. A subset of patients with gastric IM were treated to eradicate H. pylori infection. Follow-up exams with methylene blue staining, including biopsies for histology and rapid urease testing, were performed for up to 48 months. Results There were 84 subjects with a mean age of 53.0 years; 24 (29%) had gastric IM and 65 (77%) had H. pylori. There was no significant association between gastric IM and age, gender, UGI symptoms, H. pylori, or urine sodium. There was an association identified between gastric IM and a decreased pepsinogen I:II ratio (p = 0.03). Of the 11 individuals with gastric IM treated for H. pylori infection, 9 had successful therapy and underwent at least 2 follow-up examinations. The mean length of follow-up was 3.3 years. Eight of the nine (89%) had gastric IM identified histologically at the final endoscopic exam. Conclusions H. pylori infection and gastric IM are frequent findings in Southwestern Hispanics, a high-risk population for gastric cancer. Noninvasive testing is not clinically useful in distinguishing individuals within this group who harbor gastric IM. Although eradication of H. pylori infection may lead to a decrease in the amount of gastric IM in some individuals, the lesion may be detected in the majority of individuals after more than 3 years of follow-up. These data suggest that therapy for H. pylori may not eliminate the risk of gastric cancer once IM has developed.

Liver histology in anti-HCV-positive persons with normal or minimally elevated aminotransferases

The significance of a positive hepatitis C virus (HCV) screening test in asymptomatic blood donors with normal or near normal aminotransferases was studied along with the usefulness of HCV RNA polymerase chain reaction (PCR) testing for predicting chronic hepatitis in these individuals. One hundred and thirty-nine volunteer blood donors who were found positive by second generation ELISA for antibodies to HCV agreed to participate in the study. Thirty-one of them were supplemental test positive, had ALT values less than twice normal, and were followed over a minimum of 12 months. Thirteen consented to percutaneous liver biopsy and also had HCV RNA determination by PCR. Ten of the 13 subjects were positive for HCV RNA by PCR. Of the nine who were positive for HCV RNA and had adequate tissue for evaluation, seven had evidence of chronic hepatitis, three with limiting plate necrosis. Lobular inflammation was similar in severity to that found in the portal region. In addition, two had periportal fibrosis, and one had bridging fibrosis. Of the three subjects who were negative for HCV RNA, only one had portal inflammation which was limited to the portal region. None of these three had lobular changes, or periportal or bridging fibrosis. Of the three normal biopsies, two were from subjects who were negative for HCV RNA. The sensitivity and specificity of HCV RNA testing for chronic hepatitis was 87.5% and 50%, respectively, yielding an overall accuracy of 75%. We conclude that asymptomatic blood donors with antibodies to HCV, normal or mildly elevated liver tests, and HCV RNA may have abnormal liver histology indicating the potential for progressive liver disease. HCV RNA testing by PCR may be clinically useful as a noninvasive means to discriminate between those with and without chronic liver disease.

Yield of routine endoscopy beyond the duodenal bulb.

The authors determined the clinical yield, endoscopic time, and patient tolerance of routine upper endoscopy beyond the duodenal bulb. From May through October 1994, all patients undergoing routine esophagogastroduodenoscopy (EGD) were recruited for study. Each procedure was timed from start to finish by the endoscopy nurse, and, in addition, the time of the postbulbar examination was recorded. The endoscopy nurse assessed the patients comfort level when the endoscope was advanced into the duodenal bulb and again at the postbulbar region. A total of 250 EGDs were performed. There were 152 males and 98 females, with a mean age of 57.1 (range, 23-91) years. Indications for the procedure were as follows: gastroesophageal reflux disease symptoms 82, epigastric pain 64, dysphagia 46, Barretts surveillance 25, anemia 23, other research study 16, and other 61. The mean time for the procedure was 11 min and 54 s, whereas the mean time for the postbulbar examination was 46.6 s. Patients tolerated endoscope insertion well both before and during examination of the postbulbar duodenum. The only postbulbar finding that affected clinical management was a postbulbar ulcer in a patient without other ulcers who was positive for Helicobacter pylori. Although routine endoscopic examination beyond the duodenal bulb involves minimal time and is well tolerated by patients, the yield of pathologic findings is low (3.6%) and the yield of findings that alter clinical management even lower (0.4%). In patients without prior GI surgery undergoing routine EGD for indications other than suspected small bowel pathology or active upper GI bleeding, examination of the postbulbar duodenum can be considered an elective part of the procedure.

3520 THE IRREGULAR Z-LINE IN COMMUNITY PRACTICE: DO WE NEED TO BIOPSY?

Background: Subtle irregularity and short tongues of columnar appearing mucosa (CAM) at the Z-line are frequently observed during EGD. Although the risk of short segments of Barretts esophagus progressing to esophageal adenocarcinoma is not yet clear, some experts have advocated placing all patients with any length of Barretts esophagus into an endoscopic surveillance program. The frequency of intestinal metaplasia (IM) and the threshold for biopsy of such short segments in community practice have not been clearly defined. Objective: To identify the frequency of CAM and IM in the distal esophagus of patients presenting for EGD in the community setting. Methods: 207 consecutive patients presenting to the author for EGD at Exempla Lutheran Medical Center in Wheat Ridge, Colorado were studied. CAM was defined as any proximal extension of dark red mucosa as measured from the proximal heads of the gastric folds. CAM was categorized as follows: irregular Z-line, 1 cm, 2 cm, or ≥ 3 cm in length. An irregular Z-line was defined as any discrete tongue or exaggerated waviness of the Z-line which extended proximally less than 1 cm. Two to 4 biopsies were obtained with standard forceps; biopsies were taken in 4 quadrants every 2 cms for segments >3 cms. All slides were stained with a combination of PAS and Alcian blue at pH 2.5. IM was defined as specialized columnar epithelium containing goblet cells. Results: There were 104 females and 103 males with a mean age of 57.5 years. The most common indications for EGD were dysphagia (63), reflux symptoms (62), abdominal pain (40), and upper GI bleeding (33). The most common endoscopic findings were esophagitis (45), Schatzkis ring (45), peptic ulcer disease (37), normal (21), and peptic stricture (12). 42/207 patients (20.2%) had CAM of any length. 26 of these 42 patients (61.9%) had an irregular Zline. Only 2 of the 26 patients (7.7%) with an irregular Z-line had IM. This was compared to IM identified in 4/7 (57.1%) with 1 cm, 5/5 (100%) with 2 cm, and 3/4 (75%) with ≥ 3 cm of CAM. None of the patients with IM had dysplasia. In those patients with CAM who did not have IM detected, the most common finding was mild chronic inflammation of gastric cardia mucosa. Conclusions: Although an irregular Z-line is a common finding at EGD in community practice, IM is uncommonly identified at biopsy (7.7%). On the other hand, IM is frequently identified in segments of CAM at least 1 cm in length (75%). Although further studies are needed, these data would suggest that small variations of less than 1 cm in the Z-line do not require endoscopic biopsy.

P53 mutation in short segment Barrett's esophagus (SSBE)

Mutations in tumor suppressor genes have been reported in patients with Barretts esophagus. Both long and short segments of Barretts esophagus have been associated with cancer. However, the role of biomarkers specifically in patients with SSBE has not been evaluated. Aim. To study p53 mutation in patients with documented SSBE. Methods: SSBE was defined as the presence of <3cm of columnar appearing mucosa at endoscopy with intestinal metaplasia on biopsy. All specimens were stained with hematoxylin and eosin and alcian blue at pH 2 .5 . p53 mutation was identified by immunohistochemistry staining using two different antibodies, DO-I and DO-7. Results: Fifty-eight patients with SSBE were identified. All patients were male with a mean age of 63.1 -+ 1.3 years. The mean length of Barretts mucosa was 1.5 -+ 0.1cm. Ten patients had low grade dysplasia initially or at follow-up biopsy, p53 staining was positive in 2 of 58 patient biopsies with SSBE, both had low grade dysplasia. Biopsies of all other patients stained negative for p53 mutation. Conclusions: p53 mutation can be detected in patients with SSBE, especially those with dysplasia, thus supporting the malignant potential of SSBE. Studies comparing patients with SSBE and long segment Barretts esophagus (LSBE) are needed to assess whether these lesions are biologically similar with an equivalent risk for cancer development.