The Association of the Epidermal Growth Factor Receptor (EGFR) Immunoexpression With Prognostic Parameters in Adenocarcinoma Patients Receiving Neoadjuvant Treatment.

The epidermal growth factor receptor (EGFR) expression is considered to play an essential role in the pathogenesis of colorectal adenocarcinoma. This study assessed the expression and predictive/prognostic value of EGFR expression in pre-op biopsy and post-op resection specimens in patients receiving neoadjuvant radiotherapy/neoadjuvant chemoradiotherapy (NRT/NCRT). Thirty-four consecutive patients were included in this study. The association between the prognostic features and EGFR immunohistochemical expression was analyzed in pre- (n=34) and post-treatment (n=22) tissue samples in cases with available tissue blocks. Of 34, 23 (67.6%) were men. The median age was 60.50 ± 10.69 (range, 31-84) years. EGFR expression was detected in 88.2% of biopsy specimens and in 91.2% of surgical specimens. There was only slight agreement between pre-op and post-op EGFR expression scores (kappa value 0.11). There was no significant correlation between pre-op and post-op EGFR expression scores (p>0.05). Although pre-op EGFR positivity and higher pre-op EGFR scores seemed to indicate a worse prognosis, this association between pre-op EGFR expression and overall survival (OS) or disease-specific survival (DSS) did not reach statistical significance (p>0.05). The only case with a post-op EGFR score of three who died of the disease experienced local recurrence and had distant metastasis. In conclusion, EGFR positivity in pre-op biopsy samples seems to be associated with shorter survival, and increased EGFR expression in post-treatment resection specimens predicts aggressive behavior in patients with rectal adenocarcinoma who received NRT/NCRT. However, due to the molecular heterogeneity, EGFR expression status should be evaluated in resection specimens rather than in pre-op biopsy samples for optimal prognosis prediction.

Effect of intra-abdominal boric acid in the experimental adhesion model.

BACKGROUND: The continuous advancement in medical and surgical techniques has led to a rise in the frequency of abdominal operations, subsequently increasing the incidence of intra-abdominal adhesions. Over 90% of laparotomies result in postoperative intra-abdominal adhesions. This study investigates the effect of a 5% boric acid solution on the development of intra-abdominal adhesions in rats, using an adhesion model. METHODS: This study was conducted with two groups: a control group, in which the adhesion model was applied without any treatment, and a boric acid group, which was treated with a 5% boric acid solution. Each group comprised 16 rats. On the 14th postoperative day, the rats were sacrificed, re-explored, and the developed adhesions were evaluated both macroscopically and microscopically. The data from macroscopic and microscopic scoring were analyzed using the Mann-Whitney U test in the IBM Statistical Package for the Social Sciences (SPSS) Statistics 24 program. A p-value of less than 0.05 was considered statistically significant. This research was supported by the Manisa Celal Bayar University Scientific Research Projects Commission. RESULTS: A statistically significant difference was observed between the boric acid-treated group and the control group, with the boric acid group showing a significant decrease in adhesion development both macroscopically and microscopically (p<0.05). CONCLUSION: In the future, boron could play a significant role in reducing and preventing intra-abdominal adhesions after surgery. This investigation could pave the way for further research into the mechanism by which boric acid prevents the development of intra-abdominal adhesions. Moreover, it is imperative to explore the potential side effects of intra-abdominal boron application at the optimum concentration of the solution.

c-MET positivity and its relationship with histopathological findings in gastric carcinomas exhibiting HER2 gene expression.

Context: Co-expressions of receptor tyrosine kinases such as c-MET and HER2 were reported in many studies. The concomitant expression is associated with more aggressive clinical course. Aims: In this study, it was intended to investigate the correlation of the positivity of c-MET and HER2 with histopathologic findings and their impacts on prognosis. Subjects and Methods: After the decision of the ethics committee, a total of 64 cases, whose HER 2 status was studied by dual silver in situ hybridization/immunohistochemistry method, were included in the study. Immunohistochemical staining for c-MET was performed to all cases and the evaluation was performed similarly to the criteria for HER2 evaluation, but cytoplasmic staining was also considered significant. Statistical Analysis Used: The data were analyzed using SPSS 20 for Windows. Results: c-MET positivity which is considered by the score of 2+ and 3+ was found only in 34.4% of HER2 positive cases while it was 59.3% in HER2 negative cases (P = 0.045). The sole histopathological feature associated with c-MET positivity was distal gastric localization (P = 0.016). Conclusions: Even though higher rates of c-MET positivity in HER2 positive cases were stated in the literature, contrary results were obtained in this study. Comparing the HER2+/c-MET + co-expression group with the other groups, no difference was found about age, sex, macroscopic and microscopic characteristics. The presence of c-MET positivity in cases with HER2 expression suggests that c-MET expression might be associated with the resistance to Trastuzumab.

Programmed cell death ligand-1 expression in gastroenteropancreatic neuroendocrine tumors.

PURPOSE: Gastroenteropancreatic tumors (GEPNETs) is a heterogeneous disease with variable clinical course. While promising therapeutic options exist for other adult cancers, there are no new molecular-based treatments developed for GEPNETs. One of the main targets of cancer immunotherapy is the Programmed Cell Death Ligand-1 (PD-L1) pathway. Our purpose was to investigate the profile of PD-L1 expression in different organs of GEPNETs and compare the conventional immunohistochemistry (IHC) with the RNA expression analysis via real time polymerase chain reaction (RT-PCR) in order to determine which patients might be appropriate for immune check point-targeted therapy. METHODS: A total of 59 surgically or endoscopically resected GEPNET tissues were retrospectively collected. The expression of PD-L1 and mRNA was evaluated with IHC. RESULTS: The expression of PD-L1 was significantly associated with the high-grade classification (p=0.012). PD-L1 mRNA expression in tumor samples appeared to be higher compared to the corresponding normal tissues. In appendix, stomach and small intestine, the expression of PD-L1 mRNA was higher in the tumor tissues compared to the respective controls. In pancreas and colon, control tissues tend to have a higher PD-L1 mRNA expression compared to tumor tissues. PD-L1 mRNA expression was higher in GEP carcinomas (p=0.0031). CONCLUSION: RT-PCR was found to be more sensitive in detecting PD-L1 expression than conventional IHC. This study may provide an important starting point and useful background information for future research about immunotherapy for appendix, stomach and small intestine neuroendocrine carcinomas.

A Retrospective Evaluation of the Epithelial Changes/Lesions and Neoplasms of the Gallbladder in Turkey and a Review of the Existing Sampling Methods: A Multicentre Study.

OBJECTIVE: As there is continuing disagreement among the observers on the differential diagnosis between the epithelial changes/lesions and neoplasms of the gallbladder, this multicentre study was planned in order to assess the rate of the epithelial gallbladder lesions in Turkey and to propose microscopy and macroscopy protocols. MATERIAL AND METHOD: With the participation of 22 institutions around Turkey that were included in the Hepato-Pancreato-Biliary Study Group, 89,324 cholecystectomy specimens sampled from 2003 to 2016 were retrospectively evaluated. The numbers of adenocarcinomas, dysplasias, intracholecystic neoplasms/adenomas, intestinal metaplasias and reactive atypia were identified with the review of pathology reports and the regional and countrywide incidence rates were presented in percentages. RESULTS: Epithelial changes/lesions were reported in 6% of cholecystectomy materials. Of these epithelial lesions, 7% were reported as adenocarcinoma, 0.9% as high-grade dysplasia, 4% as low-grade dysplasia, 7.8% as reactive/regenerative atypia, 1.7% as neoplastic polyp, and 15.6% as intestinal metaplasia. The remaining lesions (63%) primarily included non-neoplastic polypoids/hyperplastic lesions and antral/pyloric metaplasia. There were also differences between pathology laboratories. CONCLUSION: The major causes of the difference in reporting these epithelial changes/lesions and neoplasms include the differences related to the institute's oncological surgery frequency, sampling protocols, geographical dissimilarities, and differences in the diagnoses/interpretations of the pathologists. It seems that the diagnosis may change if new sections are taken from the specimen when any epithelial abnormality is seen during microscopic examination of the cholecystectomy materials.

Gamma scintigraphy and biodistribution of (99m)Tc-cefotaxime sodium in preclinical models of bacterial infection and sterile inflammation.

(99m)Tc-cefotaxime sodium ((99m)Tc-CEF) was developed and standardized under varying conditions of reducing and antioxidant agent concentration, pH, radioactivity dose, and reducing agent type. Labeling studies were performed by changing the selected parameters one by one, and optimum labeling conditions were determined. After observing the conditions for maximum labeling efficiency and stability, lyophilized freeze dry kits were prepared accordingly. Simple method for radiolabeling of CEF with (99m)Tc has been developed and standardized. Labeling efficiency of (99m)Tc-CEF was assessed by both radio thin-layer chromatography and radio high-performance liquid chromatography and found higher than 90%. The labeled compound was found to be stable in saline and human serum up to 24 h. Two different freeze dry kits were developed and evaluated. Based on the data obtained from this study, both products were stable for 6 months with high labeling efficiency. The prepared cold kit was found sterile and pyrogen free. The bacterial infection and sterile inflammation imaging capacity of (99m)Tc-CEF was evaluated. Based on the in vivo studies, (99m)Tc-CEF has higher uptake in infected and inflamed thigh muscle than healthy thigh muscle.

The potential role of the NEK6, AURKA, AURKB, and PAK1 genes in adenomatous colorectal polyps and colorectal adenocarcinoma.

Colorectal adenomatous polyp (CRAP) is a major risk factor for the development of sporadic colorectal cancer (CRC). Histone modifications are one of the epigenetic mechanisms that may have key roles in the carcinogenesis of CRC. The objective of the present study is to investigate the alternations in the defined histone modification gene expression profiles in patients with CRAP and CRC. Histone modification enzyme key gene expressions of the CRC, CRAP, and control groups were evaluated and compared using the reverse transcription PCR (RT-PCR) array method. Gene expression analysis was performed in the CRAP group after dividing the patients into subgroups according to the polyp diameter, pathological results, and morphological parameters which are risk factors for developing CRC in patients with CRAP. PAK1, NEK6, AURKA, AURKB, HDAC1, and HDAC7 were significantly more overexpressed in CRC subjects compared to the controls (p < 0.05). PAK1, NEK6, AURKA, AURKB, and HDAC1 were significantly more overexpressed in the CRAP group compared to the controls (p < 0.005). There were no significant differences between the CRAP and CRC groups with regards to PAK1, NEK6, AURKA, or AURKB gene overexpression. PAK1, NEK6, AURKA, and AURKB were significantly in correlation with the polyp diameter as they were more overexpressed in polyps with larger diameters. In conclusion, overexpressions of NEK6, AURKA, AURKB, and PAK1 genes can be used as predictive markers to decide the colonoscopic surveillance intervals after the polypectomy procedure especially in polyps with larger diameters.

Clarithromycin resistance and 23S rRNA gene point mutations of Helicobacter pylori infection in children.

This study aims to evaluate Helicobacter pylori with clarithromycin resistant genotypes in Manisa region, Turkey. Two hundred patients, who received diagnosis of Helicobacter pylori infection histopathologically, were included. The sex, age and endoscopy indications of the patients were recorded. Polymerase chain reaction method was applied to determine the clarithromycin resistance rate and resistance genotypes at the histologic sections prepared from gastric biopsies that had been embedded in paraffin after fixation by formalin. Helicobacter pylori resistance to clarithromycin was found in 19/200 (9.5%) patients. 10/19 (52.6%) of these clarithromycin-resistant patients had A2143G mutation and 9/19 (47.4%) had A2142G mutation. A2142C mutation on 23S rRNA gene was not detected for any of the patients. Clarithromycin can be used as a first step treatment in the eradication of Helicobacter pylori for the children in our region; if the treatment fails for some patients, clarithromycin resistance, especially A2143G and A2142G mutations should be considered.

Olive Leaf Extract Improves the Atherogenic Lipid Profile in Rats Fed a High Cholesterol Diet.

Coronary heart disease because of atherosclerosis is still the most common cause of mortality. Elevated levels of low-density lipoprotein and total cholesterol are major risk factors for atherosclerotic cardiovascular disease. The aim of this study was to evaluate the effects of the olive leaf extract on serum lipid profile, early changes of atherosclerosis and endothelium-dependent relaxations in cholesterol-fed rats. For this purpose, rats were fed by 2% cholesterol-enriched or standard chow for 8 weeks. Some rats in each group were also fed orally by olive leaf extract at doses of 50 or 100 mg/kg/day. Atorvastatin at dose of 20 mg/kg of body weight daily was also given as positive control. After 8 weeks, lipid profiles of rat serums were analyzed. Antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) and degree of lipid peroxidation (malondialdehyde levels) were also measured in the hearts isolated from rats. In addition, expression of adhesion molecules and endothelium-dependent relaxations of isolated thoracic aortas of rats were evaluated. Total cholesterol and LDL-cholesterol levels were found to be increased in cholesterol-fed rats, and both doses of olive leaf extract and atorvastatin significantly decreased those levels. In conclusion, because the olive leaf extract attenuates the increased cholesterol levels, it may have beneficial effects on atherosclerosis.

Never in mitosis gene A-related kinase 6 and aurora kinase A: New gene biomarkers in the conversion from ulcerative colitis to colorectal cancer.

Ulcerative colitis (UC) is an important risk factor for colorectal cancer (CRC). Histone modifications are one of the epigenetic mechanisms that may have key roles in the carcinogenesis of CRC. At present, there are no studies comparing histone modification patterns of UC and CRC in the literature. Therefore the aim of the present study was to investigate whether genes, particularly those involved in histone modification, have value in patient monitoring with regards to CRC development in UC. Key gene expressions of the histone modification enzyme were assessed and compared in CRC, UC and control groups using the RT-PCR array technique. Patients were divided into subgroups based on the extent and duration of the disease and inflammatory burden, which are considered risk factors for CRC development in UC patients. In UC and CRC groups, a significantly higher overexpression of the NEK6 and AURKA genes compared to the control group was identified. In addition, there was a significantly higher overexpression of HDAC1 and PAK1 genes in the UC group, and of HDAC1, HDAC7, PAK1 and AURKB genes in the CRC group. NEK6, AURKA, HDAC1 and PAK1 were significantly overexpressed in patients with a longer UC duration. Overexpression of AURKA and NEK6 genes was significantly more pronounced in UC patients with more extensive colon involvement. HDAC1, HDAC7, PAK1, NEK6, AURKA and AURKB are important diagnostic and prognostic markers involved in the carcinogenesis of CRC. HDAC1, PAK1, NEK6 and AURKA may be considered as diagnostic markers to be used in CRC screening for UC patients.

Evaluation of the relation between interstitial cells of cajal (CD117) and serotonin receptor (5HT-3A) with postfundoplication dysphagia.

OBJECTIVE: The aim of the present study is to investigate the effect of Nissen fundoplication to the pacemaker cells of an intestinal system and the serotonin receptors on an ICC membrane. METHODS: Sixteen adult male rats were taken into study. Rats were divided in to the following two groups. Nissen fundoplication was performed to study group (Group 1) and no surgical procedures were applied to control group (group 2). The rats who were subjected to surgery and the rats without surgery were sacrificed on to postoperative 14 days. Specimens for the pathologic analysis were obtained from upper esophagus (group A) and esophagogastric junction (EGJ) (group B). Distribution of ICC and 5HT-3A were evaluated separately. RESULTS: There was a significant difference (p=0.01, p=0.02, respectively) regarding number of cells stained with CD117 between the group 1B-2B and group 2A-2B. Also there was a significant difference between (p=0.01, p=0.01 respectively) number of cells stained with 5HT-3A in groups 1A-1B and 2A-2B. However, no correlation was detected between group 1B-2B for 5HT-3A. CONCLUSION: A reduction in the number of ICC was observed in esophagogastric junctions of the fundoplication group but 5HT-3A distribution did not show a significant difference. A decrease in the number of ICC may be effective at postfundoplication dysphagia.

[Sinonasal-type haemangiopericytoma: a case report]. / Sinonazal tip hemanjioperisitom: bir olgu sunumu

Sinonasal-type hemangiopericytomas, which comprise less than 0.5% of all sinonasal neoplasms, arise unilaterally in the nasal cavity as polypoid masses with a mean diameter of about 3 cm. A 34-year-old female patient was admitted due to nasal obstruction and epistaxis. A polypoid mass covered with intact mucosa that originated both from the right inferior concha and lateral nasal wall was detected by nasal endoscopy. The tumor, extending from the oropharynx to the nasopharynx, was measured as 3,5x3x2 cm. Although exhibiting characteristic histopathological features and typical clinical symptoms, this case with unexpected immunohistochemical findings can provide a viewpoint on the nature of this kind of tumors.

(99m) Tc-Doxycycline hyclate: a new radiolabeled antibiotic for bacterial infection imaging.

Radiolabeled antibiotics are promising radiopharmaceuticals for the precise diagnosis and detection of infectious lesions. Doxycycline Hyclate (DOX) was chosen to investigate new (99m) Tc-labeled antibacterial agent. Ready to use freeze dry kits were formulated with optimum labeling conditions. Human serum stability, sterility, and pyrogenicity of kits were estimated, and gamma scintigraphy, in vivo biodistribution, and histopathological studies with bacterial infected rats were performed. DOX were successfully labeled by (99m) Tc with high radiochemical purity, and the labeled compound was stable in human serum. Kits were sterile, pyrogen-free, and stable up to 6 months. Static images depicted rapid distribution throughout the body and high uptake in bacterial infected thigh muscle. The uptake ratios of radiopharmaceuticals in infected thigh muscle were found above 2 up to 5 h. Five hours after injection, the rats were sacrificed, and biodistribution was determined. Samples of bacterial infected muscle, healthy muscle, blood, liver, spleen, lung, kidney, stomach, intestine, urine and heart were weighed, and the radioactivity was measured by using a gamma counter. The %ID/g of (99m) Tc-DOX was found 0.23 ± 0.06 for infected thigh muscle. According to the imaging, biodistribution, and histopathological studies, the promising characteristics of (99m) Tc-DOX make the new radiopharmaceutical valuable to examine for future studies.

Inflammatory myofibroblastic tumor of the colon with an unusual presentation of intestinal intussusception.

Inflammatory myfibroblastic tumor (IMT), also known as inflammatory pseudotumor is unusual, benign solid tumor. This tumor is commonly reported in the lungs but can be present in extrapulmonary sites as well. We present the case of a 7-year-old girl with IMT in an unusual location. The patient was admitted with abdominal pain, and ultrasound showed a solid mass in the abdomen. She was operated and colocolic intussusception secondary to a mass was found. Histologic evaluation of mass revealed IMT.

Does Helicobacter pylori treatment improve the symptoms of globus hystericus?

BACKGROUND/AIMS: Globus hystericus is a feeling of tension in the throat, irrelevant of swallowing, persisting for at least 12 weeks. Since the cause of globus hystericus is not fully described, the treatment is controversial. We aimed in this study to determine the symptoms of gastroesophageal reflux disease, upper gastrointestinal endoscopic findings, prevalence of Helicobacter pylori,and post-treatment symptoms (symptoms of gastroesophageal reflux and/or Helicobacter pylori) in patients with a diagnosis of globus hystericus. MATERIALS AND METHODS: One hundred twenty three patients were recruited from the archives of the Department of Gastroenterology and Endoscopy at Celal Bayar University Medical School between January 2009 and August 2010. RESULTS: Helicobacter pylori was positive in 75 (60%) of 123 patients with globus hystericus. Helicobacter pylori (+) patients had significantly more heartburn, regurgitation, and inlet patch in upper esophagus than Helicobacter pylori (-) patients. Significantly more Helicobacter pylori (-) patients had normal endoscopy findings when compared to Helicobacter pylori (+) patients. While 27 (50%) of Helicobacter pylori-eradicated patients had regressing globus symptoms, 12 (17.3%) of them did not have any regression in globus symptoms. Improvement in symptoms showed a positive correlation with Helicobacter pylori eradication (p=0.001). CONCLUSIONS: Helicobacter pylori rate among cases with globus sensation was similar to values in the general population. Helicobacter pylori eradication was found to decrease globus symptoms.

Diagnostic yield of upper gastrointestinal endoscopy in the evaluation of iron deficiency anemia in older children and adolescents.

Iron deficiency anemia (IDA) is frequent in childhood. Inadequate nutrition and gastrointestinal malabsorption are the frequent causes of IDA in children. But reduced iron absorption and insidious blood loss from the gastrointestinal tract has been identified as the most frequent causes of IDA in older children and adolescents. Therefore the authors evaluated the frequency and etiologies of the upper gastrointestinal system pathologies causing IDA in older pediatric population. Patients with known hematological or chronic diseases, heavy menstrual flow, and obvious blood loss were excluded from the study. Forty-four children between the ages of 9.5 and 17.5 years and diagnosed with IDA were enrolled. They underwent upper gastrointestinal endoscopy and biopsy from esophagus, stomach, and duodenum. Mean age and hemoglobin (Hb) levels of study group (32 boys, and 12 girls) were 14.6 ± 2.0 years and 7.9 ± 1.8 g/dL, respectively. Only 1 patient had a positive serology testing with anti-tissue transglutaminase and small bowel biopsy correlating with celiac disease. Endoscopy revealed abnormal findings in 25 (56.8%) patients (21 endoscopic antral gastritis, 2 active duodenal ulcers, and 2 duodenal polyps). Helicobacter pylori (HP) infection was identified by using antral histopathological evaluation in 19 of 44 children (43.2%). In 2 of duodenal samples, one patient had celiac disease, and the other one was diagnosed as giardiasis. In conclusion, there are different etiologies resulting in IDA in older children and adolescents. When older children and adolescents are found to have iron deficiency, HP infection and other gastrointestinal pathologies should be ruled out before iron deficiency treatment.

Correlation among standard endoscopy, narrow band imaging, and histopathological findings in the diagnosis of nonerosive reflux disease.

BACKGROUND AND AIMS: Gastroesophageal reflux disease (GERD) is caused by the reflux of gastric contents into the esophagus. Narrow band imaging (NBI) facilitates mucosal surface evaluation and may improve the endoscopic diagnosis of GERD. The diagnosis of GERD is based on the combination of clinical symptoms, endoscopic findings, and histological changes. In this study we aimed to show the differences between standard white light endoscopy and the NBI technique in squamo-columnar junction evaluation. We also evaluated the patients with NERD, as determined by standard white light endoscopy, using the NBI technique and histopathological mucosa examination (inflammation or normal mucosa). METHODS: A total of 60 subjects were recruited prospectively: 40 with nonerosive reflux disease (NERD) and 20 with erosive reflux disease (ERD). Patients were subjected to esophagogastroduodenoscopy and, in all of them, two biopsies were taken 2 cm above the esophagogastric junction. RESULTS: NBI was more sensitive than standard white light endoscopy in distinguishing normal endoscopic findings. Histopathological findings were more prevalent than the mucosal changes diagnosed by the standard white light endoscopy and NBI. CONCLUSION: NBI is more sensitive than white light endoscopy in detecting inflammation in NERD patients. However, histopathological evaluation is the most sensitive, therefore taking a biopsy will remain useful.

The synchronous primary carcinomas of the rectum and prostate.

The diagnosis of synchronous prostatic and rectal carcinomas is uncommon. To make a correct diagnosis, biopsies of both sites are mandatory. Pathological slides should be compared and immunohistochemical staining should be taken into consideration. In this paper, an unexpected case of synchronous rectal and prostatic carcinomas arising in an 84-year-old male with hematemesis and pelvic pain is reported. These two tumoral components have a distinctive histological appearance. Immunohistochemical evaluation confirmed the diagnosis of these synchronous tumors. This case emphasizes that rectal and prostatic carcinomas can arise simultaneously. In this situation, providing clinicopathological correlation and deciding the necessity of intraoperative consultation in proper time are extremely important.

Immunohistochemical analysis of Ki-67, p53 and Bcl-2 expression related to histological features in gastroesophageal reflux disease.

BACKGROUND/AIMS: The endoscopic and histologic findings of gastroesophageal reflux disease are usually indistinct. The current study was designed to define accurately the histology in gastroesophageal reflux disease and to develop a hypothesis that reflux produces immunohistochemical changes. METHODS: The study was based on the examination of endoscopic esophageal biopsy specimens obtained from 20 patients with evidence of reflux with 24-hour pH-meter monitoring and from 20 control subjects without clinical or endoscopic reflux. The pathogenesis of reflux esophagitis was discussed by comparing the histopathologic changes with determined Ki-67, p53 and Bcl-2 immunoreactivity. RESULTS: In this study, the presence of esophagitis was determined endoscopically in only 55% of the patients with gastroesophageal reflux disease, while microscopic esophagitis was detected in 60% of them. No correlation was found between presence of endoscopic esophagitis and microscopic esophagitis in the patients with gastroesophageal reflux disease. There was a significant difference between control cases and the patients according to histological parameters, which included basal activity (p=0.006), height of papillae (p=0.006), intraepithelial neutrophils (p=0.000), intraepithelial eosinophils (p=0.006), congestion (p=0.001), and dilated intercellular spaces (p=0.006). Immunohistochemically, there was a significant difference in the expression of p53 and Ki-67 between the three study groups (patients with/without microscopic esophagitis, controls) (p<0.05). However, there was no difference in Bcl-2 between the patients with reflux and control cases. CONCLUSIONS: In this study, we considered that microscopic esophagitis does not always accompany reflux, and the lack of reliable diagnostic histologic criteria is still a serious problem for pathologists. Immunohistochemically, an increase in cell proliferative activity and p53 protein accumulation to repair oxidative DNA damage related to reflux were observed. However, the close Bcl-2 immunoreactivity in all groups that was indicated by a weak positivity suggests that the inhibition of apoptosis may not be involved in reflux esophagitis.