Reactive Epithelial Changes Research Articles

A74 A RARE CASE OF ANTIDEPRESSANT-INDUCED LYMPHOCYTIC COLITIS IN A TEENAGER

Abstract Background The etiopathogenesis of microscopic colitis may reflect an immunological reaction in genetically predisposed individuals exposed to an external stimulus causing gut microbiota disruption. Numerous factors such as smoking, autoimmune diseases, and medications have been linked to this condition in adults. Steroids may be required as therapy. Pediatric cases of microscopic colitis have only rarely been reported. Aims Case report. Methods Retrospective single chart review and literature review of microscopic colitis in children. Results A 17-year-old female newly diagnosed with major depression disorder following intentional acetaminophen intoxication was started on sertraline, a selective serotonin reuptake inhibitor (SSRI). Within 2 months from initiation, she began to have non bloody watery diarrhea and had a 5 kg weight loss over a 1-month period . Her laboratory workup only revealed a hypochromic, microcytic anemia. Due to severity of symptoms and reluctance of treating team to discontinue sertraline, she underwent an esophagogastroduodenoscopy and ileo-colonoscopy, both showing grossly normal mucosa. Histological assessment of the colon demonstrated increased intraepithelial lymphocytes, up to 50-60 lymphocytes/100 enterocytes (normal ≤ 20 lymphocytes/100 enterocytes), with associated reactive superficial epithelial changes including goblet cell and mucin depletion, compatible with lymphocytic colitis (Figure1). Sertraline was weaned off, and gastrointestinal symptoms resolved completely. A repeat sigmoidoscopy 5 months later confirmed complete normalization of the histology. Conclusions Microscopic Colitis encompasses two disorders, lymphocytic colitis and collagenous colitis, in which the endoscopic appearance is unremarkable, but histological changes are diagnostic. The clinical manifestations of both are similar and typically include chronic non bloody watery diarrhea, weight loss and abdominal pain. Certain medications have been implicated in causing lymphocytic colitis, including SSRIs. SSRIs historically have not been frequently prescribed in pediatrics, but their use has increased in recent years. The complete resolution of symptoms and histology, without the need for any medical therapy, strongly supports that this lymphocytic colitis was caused by sertraline. The association of lymphocytic colitis with sertraline is not well-known among pediatric practitioners: neither the pediatrician nor psychiatrist in our case were aware of such a possibility. This case highlights that medication adverse events, even if rare, should always be considered when chronology is supportive, and at times, simple discontinuation of the drug is sufficient to completely resolve the issue. Funding Agencies None

Epithelial overexpression of IL-33 induces eosinophilic esophagitis dependent on IL-13

BackgroundEosinophilic esophagitis (EoE) is an increasingly common inflammatory condition of the esophagus; however, the underlying immunologic mechanisms remain poorly understood. The epithelium-derived cytokine IL-33 is associated with type 2 immune responses and elevated in esophageal biopsies from EoE subjects. ObjectiveWe hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE. MethodsWe evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-33 (saIL-33) in a novel transgenic mouse, EoE33. EoE33 mice were analyzed for clinical and immunologic phenotypes. Esophageal contractility was assessed. Epithelial cytokine responses were analyzed in three-dimensional organoids. EoE33 phenotypes were further characterized in ST2-/-, eosinophil-deficient, and IL-13-/- mice. Finally, EoE33 mice were treated with dexamethasone. ResultsEoE33 mice displayed ST2-dependent, EoE-like pathology and failed to thrive. Esophageal tissue remodeling and inflammation included basal zone hyperplasia, eosinophilia, mast cells, and Th2 cells. Marked increases in levels of type 2 cytokines, including IL-13, and molecules associated with immune responses and tissue remodeling were observed. Esophageal organoids suggested reactive epithelial changes. Genetic deletion of IL-13 in EoE33 mice abrogated pathological changes in vivo. EoE33 mice were steroid responsive. ConclusionIL-33 overexpression by the esophageal epithelium generated immunopathology and clinical phenotypes resembling human EoE. IL-33 may play a pivotal role in the etiology of EoE by activating the IL-13 pathway. EoE33 mice are a robust experimental platform for mechanistic investigation and translational discovery.

Polypoid colorectal endometriosis with abundant leiomyoma-like smooth muscle cell proliferation treated by endoscopic resection.

A 55-year-old female patient with abdominal pain was referred for resection of an atypical lesion in the descending colon after office-based colonoscopy. Endoscopic visualization of the estimated 15-mm nodular lesion with a broad pedicle at 11 o´clock appeared not consistent with adenoma, although minor mucosal changes, potentially related to previous biopsies were discernible (Fig. 1A). Corresponding to the endoscopic aspect, no submucosal injection of indigo carmine was achievable, however, endoscopic resection was, nonetheless, pursued to achieve tissue diagnosis (Fig. 1B). Therefore, the lesion was cautiously snare resected in a superficial manner (Fig. 1C), and post-interventional evaluation of the resection defect excluded perforation (Fig. 1D). The further clinical course was uneventful, and, with a view to histopathology, the patient was referred for gynecological care. Indeed, pathology indicated an abundant leiomyoma-like nodular smooth muscle cell proliferation with minor reactive epithelial changes with endometrial glands and stroma in between (Fig. 2A), Closer-up scrutinization of endometrial tissue elements excluded dysplastic changes (Fig. 2B). Dedicated immunohistochemistry for endometrial structures highlighted the localization around the nodular smooth muscle cell proliferation (Fig. 2C) with desmin immunoreactivity (Fig. 2D). Intriguingly, hormonal receptor immunohistochemistries indicated marked positivity in the endometrial tissue plane as well as within the leiomyoma-like nodule (Fig. 2E, F). The latter finding rather suggests a reactive nature over coincident leiomyoma. Fig. 2(A) Abundant leiomyoma-like nodular smooth muscle cell proliferation with minor reactive epithelial changes with endometrial glands and stroma in between. (H&E, x1.6). (B) Closer-up demonstration of endometrial tissue elements without dysplasia. (H&E, x5) (C) Dedicated immunohistochemistry for endometrial structures pinpoints the localization around the nodular smooth muscle cell proliferation (CD10, x1.6), (D) which exhibits strong desmin immunoreactivity. (desmin, x1.6) (E, F) Hormonal receptor immunohistochemistry, in addition, indicated marked positivity in the endometrial tissue plane as well as within the leiomyoma-like nodule, rather suggestive of its reactive nature. (estrogen (ER) and progesterone receptor (PR), x2.5 each). View Large Image Figure Viewer Download Hi-res image

S2247 Gastric Irritation Noted in Patients Using New Tablet-Based Colonoscopy Preparation

Introduction: In November 2020, the FDA approved a novel colonoscopy preparation, a tablet-based bowel prep containing poorly absorbed sulfate salts. This case series includes 3 patients undergoing upper and lower endoscopy who were found to have gastric irritation thought to be caused by this bowel preparation. Case Description/Methods: A 35-year-old male with gastroesophageal reflux presented with 5-day history of hematochezia and abdominal pain. He underwent colonoscopy which showed internal hemorrhoids and esophogastroduodenoscopy (EGD) showed ulceration of the stomach body (Figure, top left). Biopsies showed focal active gastritis and superficial erosion without H. pylori organisms. The patient started daily PPI and 3 months later repeat EGD showed normal mucosa both visually and pathologically. A 59-year-old female endorsed abdominal bloating and heartburn after completing treatment for H. pylori 1-month prior. She underwent EGD with colonoscopy (for screening). EGD showed multiple diminutive round erythematous spots in the stomach antrum with pinpoint foci of dark heme suggestive of hemorrhagic gastritis (Figure, top right). Biopsies showed moderate inactive chronic inflammation without H. pylori organisms. A 70-year-old female requested endoscopy as she had a personal history of remote H. pylori infection and her father had gastric cancer. On EGD, there were superficial erosions in the lesser curve of the stomach (Figure, bottom 3). Biopsies were obtained and showed gastric mucosa with reactive epithelial changes without evidence of H. pylori infection. Discussion: The preparation consists of 24 tablets total, each taken with 16 ounces of water. The ingredients include magnesium sulfate, potassium chloride, and sodium sulfate. The sulfate salts are responsible for the osmotic and therefore laxative effects of the medication. Potassium chloride is included to avoid diarrhea induced hypokalemia. Potassium chloride is a mucosal irritant that has been reported to cause upper gastrointestinal ulcers and erosions. In each case, gastric irritation was an unexpected finding in a patient without significant risk factors for developing gastric ulcers. The common factor among them all is the same tablet-based preparation used for colonoscopy. Noted was a similar pattern of ulceration in the gastric antrum and body noted in these patients, which was in a pattern of the tablets resting on the greater curve of the stomach. While gastric ulceration may be asymptomatic, it may lead to diagnostic confusion and further unnecessary workup.Figure 1.: Colonoscopy images.

CASE REPORT: POST-MEGASTENT DUODENAL POLYP

Introduction
 Most duodenal polyps are non-neoplastic. Instead, they represent regenerative/hyperplastic nodules of foveolar epithelium or Brunner gland proliferation (38%). Other less common polyps include heterotopic (6%) and neoplastic lesions (11%) (1). Adenomas of intestinal type are the most common (89%), followed by adenomatous lesions that present a gastric phenotype: PGAs (8%) and foveolar-type adenomas (3%) (2).
 Non-neoplastic duodenal polyps, most of which represent regenerative inflammatory (pseudo) polyps, are predominantly localized in the bulb (80%) (1). The majority are associated with duodenitis, especially in the setting of peptic injury, and are less commonly associated with inflammatory bowel disease or rare conditions such as primary immunodeficiencies. (3). Histologically, non-neoplastic duodenal polyps may resemble gastric hyperplastic polyps and frequently show metaplastic foveolar epithelium with active inflammation and/or erosion, reactive epithelial changes, seamless transition with the surrounding epithelium, and surface maturation. They may also simply be composed of granulation tissue. It is worth underscoring that some of these polyps are neoplastic. Some hyperplastic polyps harbor KRAS and BRAF mutations and tend to show serrated features, similar to their microvascular colonic counterparts (4). Duodenal hyperplastic polyps with KRAS mutation may represent precursor lesions of duodenal traditional serrated adenomas (4). The polypoid heterotopic gastric mucosa is another frequent type of duodenal polyps. As opposed to the peptic injury-induced foveolar metaplasia, lesions of this type also contain clusters of oxyntic glands under the surface of the foveolar epithelium. Duodenal gastric heterotopia is associated with FGPs and PPI therapy.

S2017 Esophagitis in Metastatic Lung Adenocarcinoma Associated With Pembrolizumab

INTRODUCTION: Pembrolizumab, a monoclonal antibody against programmed death receptor 1 (PD-1), is a form of immunotherapy used in multiple malignancies. PD-1 inhibitors have been associated with numerous “immune-related adverse events” (irAEs) affecting most organs in the body. IrAEs in the lower gastrointestinal tract have been widely reported, with only few in the upper GI tract. We present a case of acute, grade 3 esophagitis in a patient on pembrolizumab. CASE DESCRIPTION/METHODS: Case report and literature review. We searched the words “esophagitis” “immune checkpoint inhibitors” “pembrolizumab” on PubMed. A 70-year-old male was admitted to the hospital with a 1-month history of progressive dysphagia and odynophagia. Medical history was notable for metastatic lung adenocarcinoma (stage T1cN3M1c) with a tumor proportion score of 95% positive PDL-1. Patient received 31 cycles of pembrolizumab 200mg IV prior to symptom onset. Physical exam demonstrated buccal mucosa swelling and oral candidiasis upon admission. With candida esophagitis as the primary differential, patient was started on IV fluconazole 200mg q24 hours with a 400mg loading dose. After 48 hours of IV fluconazole, symptoms did not improve; Gastroenterology was consulted. An esophagogastroduodenoscopy was performed which demonstrated linear furrows and esophagitis throughout the whole esophagus and no signs of candidal infection. Biopsy showed acute esophagitis with ulceration, reactive epithelial changes, and granulation tissue. Patient was started on IV methylprednisolone 60 mg for ICI-associated esophagitis. Dysphagia improved after two days of IV steroids. Oral prednisone was continued and pembrolizumab was held. Steroid dose was gradually tapered. Tumor progression was not observed four months after discontinuation of pembrolizumab and it was not reinitiated. DISCUSSION: Immune checkpoint inhibitor therapies are associated with a wide range of adverse events that can include the upper gastrointestinal system. Management includes initiation of corticosteroids and cessation of chemotherapy in severe cases. Early recognition and timely initiation of appropriate therapy are the keys to optimal outcomes. With the growing use of pembrolizumab in oncology, physicians must be aware of all potential irAEs. This case is one of the first to highlight acute esophagitis as one of its irAE. We conclude that close monitoring for manifestations of esophagitis is crucial when prescribing PD-1 inhibitors.Figure 1.: Linear furrows and esophagitis in the mid-esophagus.

DNA flow cytometric analysis of paraffin-embedded tissue for the diagnosis of malignancy in bile duct biopsies

Differentiation of reactive versus neoplastic epithelial changes can be challenging in bile duct biopsies. The samples are often scant, distorted, and mixed with significant inflammation, ulceration, and/or debris. Histological confirmation of malignancy is often required before the initiation of surgical therapy, and an erroneous diagnosis of malignancy can lead to unnecessary clinical management. Aneuploidy assessment by DNA flow cytometry was performed on formalin-fixed paraffin-embedded (FFPE) tissue from 63 bile duct biopsies: 10 with a malignant diagnosis (7 with adenocarcinoma and 3with at least high-grade dysplasia [HGD]); 3 with an atypicaldiagnosis showing rare atypical glands/cells, concerning but not definite for malignancy; 28 likely reactivebiopsies with acute/chronic inflammation, ulceration, and/or mild nuclear atypia; and 22 additional benign biopsies without significant inflammation, ulceration, or nuclear atypia. Aneuploidy was detected in 7 (70%) of the 10 biopsies with definite neoplasia (5 of 7 adenocarcinoma cases and 2 of 3at least HGD cases), all 3 (100%) atypicalbiopsies, and none of the 50 benign biopsies. All 3 atypicalcases with aneuploidy were subsequently found to have adenocarcinoma (n=2) or HGD (n=1). Among the 2 cases of at least HGD with aneuploidy, 1 case developed adenocarcinoma, but no follow-up information was available in the other case. The remaining 1 case of at least HGD, despite having normal DNA content, was found to have adenocarcinoma on follow-up. None of the 50 benign cases (further supported by normal DNA content) developed adenocarcinoma within a mean follow-up time of 37 months (range: 0-282 months). The estimated sensitivity of aneuploidy as a diagnostic marker of malignancy (adenocarcinoma and HGD) was 70%, with the specificity of 100%, positive predictive value of 100%, and negative predictive value of 94%. In conclusion, DNA flow cytometry using FFPE tissue from bile duct biopsies demonstrates a high rate of aneuploidy (70%) in malignant casesand normal DNA content in all benign biopsies. Although the sample size is small, the results indicate that this assay can be potentially useful in challenging atypicalcases, where morphological evaluation is limited by scarcity of atypical glands/cells, inflammation, and/or ulceration.

Modeling Epithelial Homeostasis and Reactive Epithelial Changes in Human and Murine Three-Dimensional Esophageal Organoids.

The homeostatic proliferation-differentiation gradient in the esophageal epithelium is perturbed under inflammatory disease conditions such as gastroesophageal reflux disease and eosinophilic esophagitis. Herein we describe the protocols for rapid generation (<14 days) and characterization of single-cell-derived, three-dimensional (3D) esophageal organoids from human subjects and mice with normal esophageal mucosa or inflammatory disease conditions. While 3D organoids recapitulate normal epithelial renewal, proliferation, and differentiation, non-cell autonomous reactive epithelial changes under inflammatory conditions are evaluated in the absence of the inflammatory milieu. Reactive epithelial changes are reconstituted upon exposure to exogenous recombinant cytokines. These changes are modulated pharmacologically or genetically ex vivo. Molecular, structural, and functional changes are characterized by morphology, flow cytometry, biochemistry, and gene expression analyses. Esophageal 3D organoids can be translated for the development of personalized medicine in assessment of individual cytokine sensitivity and molecularly targeted therapeutics in esophagitis patients © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Generation of esophageal organoids from biopsy or murine esophageal epithelial sheets Basic Protocol 2: Propagation and cryopreservation of esophageal organoids Basic Protocol 3: Harvesting of esophageal organoids for RNA isolation, immunohistochemistry, and evaluation of 3D architecture Basic Protocol 4: Modeling of reactive epithelium in esophageal organoids.

Immunohistochemical Characterization of Reactive Epithelial Changes in Odontogenic Keratocysts

Odontogenic keratocysts (OKCs) have a diagnostic thin epithelial lining characterised by a linear epithelial connective tissue interface generally lacking inflammatory changes, basal palisading of the nuclei and a wavy parakeratotic layer on the surface. This typical epithelium may convert to a thicker non-keratinizing one with rete pegs and a relatively flat surface after operative decompression. The aim was to characterize this type of epithelial change by immunohistochemistry for bcl2, keratin17, 10 and 19. Eleven out of 33 archived OKCs demonstrated an altered epithelium related to previous biopsy, decompressing drainage or inflammation. The typical basal bcl2 staining was lost in 10/11 cases; transepithelial CK17 was lost or markedly reduced in 9/11 cases. CK10 displayed a segmental upper layer staining in OKCs, and its loss or partial loss in the altered epithelium did not differ from negative areas of OKCs. CK19 displayed various staining patterns in the altered epithelium from lost to maintained in a patchy transepithelial distribution, the latter of which did not differ from the typical OKC staining pattern. Three of four non-keratinizing epithelial linings with basal palisading displayed immunostaining reminiscent of typical OKC epithelium. The lack of a typical epithelium is not sufficient to exclude the diagnosis of OKC if the sampling is not generous (e.g. biopsy), and the presence of non-keratinizing epithelium with basal palisading and an immunophenotype characteristic of OKC (basal bcl2, patchy or diffuse CK17 and upper layer CK10 positivity) may be consistent with the OKC diagnosis even in the absence of typical epithelial lining.

3211 An Incidental Duodenal Lymphangioma Presenting as Diarrhea

Introduction: The small bowel is a rare site for neoplasia and only account for over 3% of the cases in the digestive tract. Lymphangiomas are benign tumors formed by dilated lymphatic channels that occur more commonly in the neck and axillary regions. Duodenal lymphangiomas are extremely rare in the adult population. It s thought to be a benign congenital malformation of the lymphatic vasculature that is able to grow to form a mass lesion. Their clinical presentation ranges from asymptomatic to obscure bleeding, small bowel obstruction, intussusception or even volvulus. We present a case of a duodenal lymphangioma presenting with chronic abdominal pain and diarrhea. CASE DESCRIPTION/METHODS: A 37-year-old male with no significant past medical history presented with chronic diarrhea, constipation and abdominal discomfort for 3 years. Physical examination and laboratory data were in the normal limits. Remainder of his infectious and inflammatory workup for diarrhea was negative. He underwent endoscopy which revealed a 1-cm polypoid submucosal lesion in the post-bulbar area. Multiple deep bites-on-bite biopsies were obtained from the lesion. Histological examination showed dilated lymphatics with reactive epithelial changes, consistent with Lymphangioma. During the follow up visit the patient referred improvement of the presenting symptoms. DISCUSSION: Lymphangiomas of the duodenum are a very rare lymphatic system tumor. The clinical presentations are usually variable and nonspecific and may mimic a variety of vague abdominal symptoms like abdominal discomfort, diarrhea, anorexia, nausea, and vomiting. These lesions typically exist as small incidental polyps; however, some of these tumors present as mass lesions capable of causing bowel obstruction, abdominal pain, and gastrointestinal bleeding. By endoscopic examination, they usually appear as a sessile or semi-pedunculated mass with smooth surface mucosa with lymphatic cystic dilatation with a whitish granular appearance. These benign tumors require treatment if they are accompanied by symptoms and complications such as infection, obstruction and hemorrhage. Endoscopic unroofing or polypectomy has become the treatment of choice for small to intermediate lymphangiomas. Physicians must thus be cognizant of the differentials for small bowel nodules in order to avoid unnecessary surgical interventions.

P126 MULTIPLE SIGNALING PATHWAY DEFECTS IN THE INTESTINAL STEM CELL NICHE LIKELY TRIGGER CD-LIKE ILEITIS IN SAMP1/YITFC MICE

Intestinal epithelial barrier dysfunction is considered as a risk factor in the pathogenesis of Crohn’s disease (CD), and since there is no FDA approved therapy available, there is a need for identifying a relevant model to study and test therapies to correct this defect. Previously, we demonstrated that inflammatory environment of CD affects properties of intestinal stem cell (ISC) niche, ablating its ability to form enteroids (EnOs) in our mouse model for CD-like ileitis (SAMP/YitFc, SAMP) (doi.org/10.1016/S0016-5085(17)32213-8). However, EnOs from SAMP mice even prior to disease onset (5-wks, SAMP-5) harbor impaired features, such as smaller size (2.6 ± 0.4 vs 3.9 ± 0.2 fold to ctrl at day 1, P=0.003), number (0.6 ± 0.1 fold to ctrl, P=0.000), reduced viability (63.7%±7.5 vs ctrl P=0.003) and rudimental branching complexity [cyst-like structures (42.7%±2.3 vs 11%±1.2)], compared to controls (ctrls). These EnOs produce exacerbated expression of genes involved in epithelial secretory cell functions when challenged with purified bacterial ligands, such as LPS [higher Muc2 (10.8 ± 3.2 vs 2.5 ± 1.8 P=0.00), Lyz (11.0 ± 5.2 vs 1.1 ± 0.4 P=0.00), Reg3γ (6.7 ± 9.9 vs 1.1 ± 0.5 P=0.04), Crp (7.4 ± 5.4 vs 1.3 ± 0.6 P=0.05), and Defa1 (4006.0 ± 1472.5 vs 2.1 ± 0.7 P=0.00) mRNA vs AKR EnOs]. To further investigate this phenotype, we generated the first high-resolution transcriptional profile of SAMP ISC niche by laser capture microdissection and RNA sequencing. We found that signaling pathways involved in the cellular energy machinery were dramatically reduced in inflamed SAMP (25-wks, SAMP-25) ISC niche compared to that of inflammation-free mice [mitochondrial energy metabolism (P ≤ 0.00, Padj ≤ 0.002, normalized enrichment score NES ≤ -2.4); oxidative phosphorylation (P ≤ 0.00 Padj ≤ 0.001 NES ≤ -2.5)]. Fibrosis (P ≤ 0.04 Padj≤ 0.09 NES ≤ 1.3) and UPR (P ≤ 0.01 Padj ≤ 0.03 NES ≤ 1.5) pathways were enriched in SAMP-25 ISC niche compared to ctrls, but not to that of SAMP-5 mice. Bile acid metabolism (P ≤ 0.00, Padj ≤ 0.002 NES ≤ -1.8), ROS (P ≤ 0.001 Padj ≤ 0.003 NES ≤ -1.8), Wnt3a (P ≤ 0.001 Padj ≤ 0.01 NES ≤ -1.8), and Notch1 (P ≤ 0.001 Padj ≤ 0.02 NES ≤ -1.8) pathways were decrease in SAMP-25 ISC niche compared to ctrls, but not to that of SAMP-5 mice. Collectively, these data suggest that multiple signaling pathways contribute to ISC niche defect in SAMP mice, and that many key biological functions are already altered prior to ileitis onset and may be responsible for disease initiation. Finally, the evidence that altered gene expression is maintained in ex vivo expanded EnOs indicates that these cultures recapitulate reactive epithelial changes specific of experimental CD. This aspect is of paramount importance since it emphasizes the physiologically relevant value of EnOs generated from SAMP mice, rather than those originated from healthy individuals, to mimic CD-like ileitis.

P126 MULTIPLE SIGNALING PATHWAY DEFECTS IN THE INTESTINAL STEM CELL NICHE LIKELY TRIGGER CD-LIKE ILEITIS IN SAMP1/YITFC MICE

Intestinal epithelial barrier dysfunction is considered as a risk factor in the pathogenesis of Crohn’s disease (CD), and since there is no FDA approved therapy available, there is a need for identifying a relevant model to study and test therapies to correct this defect. Previously, we demonstrated that inflammatory environment of CD affects properties of intestinal stem cell (ISC) niche, ablating its ability to form enteroids (EnOs) in our mouse model for CD-like ileitis (SAMP/YitFc, SAMP) (doi.org/10.1016/S0016-5085(17)32213-8). However, EnOs from SAMP mice even prior to disease onset (5-wks, SAMP-5) harbor impaired features, such as smaller size (2.6 ± 0.4 vs 3.9 ± 0.2 fold to ctrl at day 1, P=0.003), number (0.6 ± 0.1 fold to ctrl, P=0.000), reduced viability (63.7%±7.5 vs ctrl P=0.003) and rudimental branching complexity [cyst-like structures (42.7%±2.3 vs 11%±1.2)], compared to controls (ctrls). These EnOs produce exacerbated expression of genes involved in epithelial secretory cell functions when challenged with purified bacterial ligands, such as LPS [higher Muc2 (10.8 ± 3.2 vs 2.5 ± 1.8 P=0.00), Lyz (11.0 ± 5.2 vs 1.1 ± 0.4 P=0.00), Reg3γ (6.7 ± 9.9 vs 1.1 ± 0.5 P=0.04), Crp (7.4 ± 5.4 vs 1.3 ± 0.6 P=0.05), and Defa1 (4006.0 ± 1472.5 vs 2.1 ± 0.7 P=0.00) mRNA vs AKR EnOs]. To further investigate this phenotype, we generated the first high-resolution transcriptional profile of SAMP ISC niche by laser capture microdissection and RNA sequencing. We found that signaling pathways involved in the cellular energy machinery were dramatically reduced in inflamed SAMP (25-wks, SAMP-25) ISC niche compared to that of inflammation-free mice [mitochondrial energy metabolism (P ≤ 0.00, Padj ≤ 0.002, normalized enrichment score NES ≤ -2.4); oxidative phosphorylation (P ≤ 0.00 Padj ≤ 0.001 NES ≤ -2.5)]. Fibrosis (P ≤ 0.04 Padj≤ 0.09 NES ≤ 1.3) and UPR (P ≤ 0.01 Padj ≤ 0.03 NES ≤ 1.5) pathways were enriched in SAMP-25 ISC niche compared to ctrls, but not to that of SAMP-5 mice. Bile acid metabolism (P ≤ 0.00, Padj ≤ 0.002 NES ≤ -1.8), ROS (P ≤ 0.001 Padj ≤ 0.003 NES ≤ -1.8), Wnt3a (P ≤ 0.001 Padj ≤ 0.01 NES ≤ -1.8), and Notch1 (P ≤ 0.001 Padj ≤ 0.02 NES ≤ -1.8) pathways were decrease in SAMP-25 ISC niche compared to ctrls, but not to that of SAMP-5 mice. Collectively, these data suggest that multiple signaling pathways contribute to ISC niche defect in SAMP mice, and that many key biological functions are already altered prior to ileitis onset and may be responsible for disease initiation. Finally, the evidence that altered gene expression is maintained in ex vivo expanded EnOs indicates that these cultures recapitulate reactive epithelial changes specific of experimental CD. This aspect is of paramount importance since it emphasizes the physiologically relevant value of EnOs generated from SAMP mice, rather than those originated from healthy individuals, to mimic CD-like ileitis.

Tracheal Aspirate Cytology of 43 High-Risk Neonates to Predict Bronchopulmonary Dysplasia Early

The main goal of this study was to assess the cytological evaluation of tracheal aspirate, in order to predict the early diagnosis of bronchopulmonary dysplasia (BPD) in high-risk babies during mechanical ventilation. Method: Samples from 43 infants (aged < 34 weeks and weighed ≤ 1500 g) were examined cytologically; who were admitted to Pediatric Intensive Care Units and diagnosed as respiratory distress syndrome by clinical and radiological criteria. Results: Up to 150 tracheal aspirates from 43 infants were examined to demonstrate cytological changes in bronchial epithelial cells that progressed to dysplasia. It was cytologically designated Class III. According to cytological criteria, all intubated infants had reactive hyperplastic and metaplastic epithelial changes. There were dysplastic changes in 23 out of 33 who developed BPD and 7 out of 40 who had a normal outcome. The variation between the numbers of neonates that had dysplasia in the BPD and the non-BPD group was significant (P < 0.002 by chi-square test). Conclusion: In order to monitor the development of lung injury and repair, tracheal aspirate cytology is simple, non-invasive and fast. Cytological monitoring of respiratory distress infants may be helpful in the early diagnosis and prognosis of the developing BPD. Evaluating new BPD preventive treatment schemes may also be valuable.

Coughing up a Polyp: A Rare Cause of Dysphagia!

Fibrovascular polyps are rare, benign intraluminal lesions composed of fibrous, vascular and adipose tissues. They tend to be large and pedunculated and most commonly arise in the proximal esophagus. The incidence is higher in men and typically present in the 6th or 7th decade of life. A 74-year-old male presented with intermittent symptoms of dysphagia and episodes of choking in which he would cough up a mass and then swallow it again. He denied any odynophagia or respiratory distress between the episodes. There were no reports of weight loss or anemia. Upper endoscopy showed a proximal cervical submucosal lesion. A CT scan revealed a low-density lesion within the superior esophagus and a barium swallow showed a large pedunculated filling defect with a visible stalk extending superiorly within the upper esophagus. Further examination by endoscopic ultrasound showed a long esophageal polyp from the area immediately below the vocal cords extending down about 5cm. The polyp was estimated to be at the level of the upper esophageal sphincter area/hypopharynx (Figure 1). The patient was ultimately referred to ENT for endoscopic resection of the hypopharyngeal mass. The polyp, measuring about 6cm in length and 3cm in width, was resected en bloc (Figure 2). The patient tolerated the procedure well and was discharged the following day with only moderate odynophagia that soon resolved. Pathology was benign with the polyp described as a fibroepithelial lesion with focal surface erosion, reactive epithelial changes, and marked vascular congestion. Fibrovascular polyps are rare, benign polyps. While the exact etiology is unknown, it is thought that these types of polyps arise from redundant mucosal folds that slowly elongate over time due to constant traction from peristaltic activity. They tend to be slow growing and are often able to reach a large size before discovery. The most common presentation is dysphagia followed by globus sensation, but they can also cause anemia, weight loss and odynophagia. The most severe complication is regurgitation of the polyp into the oral cavity which can lead to asphyxiation. Despite different imaging modalities, these polyps are often misdiagnosed or missed, especially on EGD where they can resemble normal mucosa or lay flat against the lumen. Prompt removal by endoscopic or surgical resection is important to prevent potentially fatal complications.1815_A Figure 1. Imaging1815_B Figure 2. fibrovascular polyp

Incidental Finding of a Colonic Gastrointestinal Stromal Tumor (GIST) in Screening Colonoscopy: A Case Report and Review of Literature

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gut. GISTs arise due to mutation in the c-kit tyrosine kinase of the interstitial cells of cajal (ICCs) that leads to continuously activated state of tyrosine kinase and thus results in formation of GISTs. GISTs are most common in stomach (75%) and small intestine (25%). Less than 5 % of GISTs occur in colon and rectum. We present a 50 year old male who underwent a routine screening colonoscopy and was otherwise asymptomatic. Physical examination was unremarkable. Past medical history was significant for developmental delay and chronic constipation. Colonoscopy revealed a submucosal appearing lesion with an overlying ulcer at the hepatic flexure. Histopathology revealed spindle cells are arranged in a storiform-type pattern with chronic inflammatory cell infiltrate including several eosinophils, reactive epithelial cell changes and focal ulceration without any adenomatous change is observed. Immunohistochemical stains were positive for DOG -1 and CD117. CT scan of the abdomen with contrast did not reveal any evidence of metastatic lesions. GISTs account for less than 1% of gastrointestinal (GI) malignancies and only make up to 0.1% of colorectal tumors. A few other cases of colonic GIST have been reported in literature, however, they are still rare and account for less than 2% of all GISTs. Median age of presentation is 60 years with a slight male predominance. The most common clinical presentation is abdominal pain followed by gastrointestinal bleeding, obstruction and perforation. CD117 is the most important diagnostic marker and is positive in more than 95% of cases and CD34 is positive in 70% of cases. The most common cellular morphology noted in histopathology is spindle cell type followed by epithelioid and mixed cellular types. Approximately 30% of GISTs have malignant potential. Prognosis depends on the size of the tumor, histology, mitotic potential and local invasion. CT scan with contrast is the preferred imaging modality of choice for initial staging. Treatment is surgical resection and adjuvant therapy with Imatinib (tyrosine kinase inhibitor). Close surveillance is recommended in the first 3 to 5 years after treatment due to maximum risk of recurrence within that time frame. A screening colonoscopy prevented adverse outcomes in this patient who could not report symptoms due to intellectual disability.1533_A Figure 1. GIST CD117 Positive1533_B Figure 2. GIST - Spindle cell histopathology1533_C Figure 3. Hepatic flexure lesion with a central ulceration

A Rare Case of Hyperplastic Proximal Esophageal Polyps With Foveolar Dysplasia

A 62-year-old male with long-standing esophageal reflux underwent endoscopy at an outside institution that reported multiple polypoid lesions in upper esophagus and a small focal area of nodular mucosa at the gastroesophageal junction(GEJ). Biopsies of the proximal esophageal polyps demonstrated hyperplastic mucosa with ulceration, reactive epithelial changes, and focal intestinal metaplasia. Biopsies from the nodular GEJ mucosa were described as Barrett’s esophagus with low grade dysplasia. An upper endoscopy performed at our medical center found multiple semi-pedunculated esophageal polyps between 18-24 cm from the incisors (Figure A).Endosonographically the polypoid lesions were confined to the mucosa with normal underlying wall layers (Figure B). Patient underwent endoscopic mucosal resection (EMR) using a multi-band mucosectomy technique. Hematoxylin and eosin staining of the EMR specimens showed gastric and intestinal metaplasia, featuring cubital to columnar cells with pale clear to light eosinophilic cytoplasm and round to oval nuclei (Figure C). MUC5AC (a marker of gastric foveolar mucin) was positive in the specimen (Figure D); whereas intestinal markers MUC2, CDX-2 and Villin, were negative. The impression of the gastrointestinal pathologists was hyperplastic polyp with foveolar dysplasia. At a follow-up endoscopy 3 months later, smooth mucosal scarring was noted with no residual polypoid tissue or gastric heterotopia.

The Esophageal Organoid System Reveals Functional Interplay Between Notch and Cytokines in Reactive EpithelialChanges.

Background & AimsAberrations in the esophageal proliferation-differentiation gradient are histologic hallmarks in eosinophilic esophagitis (EoE) and gastroesophageal reflux disease. A reliable protocol to grow 3-dimensional (3D) esophageal organoids is needed to study esophageal epithelial homeostasis under physiological and pathologic conditions.MethodsWe modified keratinocyte-serum free medium to grow 3D organoids from endoscopic esophageal biopsies, immortalized human esophageal epithelial cells, and murine esophagi. Morphologic and functional characterization of 3D organoids was performed following genetic and pharmacologic modifications or exposure to EoE-relevant cytokines. The Notch pathway was evaluated by transfection assays and by gene expression analyses in vitro and in biopsies.ResultsBoth murine and human esophageal 3D organoids displayed an explicit proliferation-differentiation gradient. Notch inhibition accumulated undifferentiated basal keratinocytes with deregulated squamous cell differentiation in organoids. EoE patient-derived 3D organoids displayed normal epithelial structure ex vivo in the absence of the EoE inflammatory milieu. Stimulation of esophageal 3D organoids with EoE-relevant cytokines resulted in a phenocopy of Notch inhibition in organoid 3D structures with recapitulation of reactive epithelial changes in EoE biopsies, where Notch3 expression was significantly decreased in EoE compared with control subjects.ConclusionsEsophageal 3D organoids serve as a novel platform to investigate regulatory mechanisms in squamous epithelial homeostasis in the context of EoE and other diseases. Notch-mediated squamous cell differentiation is suppressed by cytokines known to be involved in EoE, suggesting that this may contribute to epithelial phenotypes associated with disease. Genetic and pharmacologic manipulations establish proof of concept for the utility of organoids for future studies and personalized medicine in EoE and other esophageal diseases.

A Tough Pill to Swallow: A Case of Rituximab-associated Esophageal Ulcers

Idiopathic giant esophageal ulcers were initially reported in patients with acquired immunodeficiency syndrome (AIDS), and later in other immunocompromised patients such as transplant recipients. However, there are no reported cases of esophageal ulcers associated with rituximab in lymphoma patients to our knowledge. A 44-year old male with history of Stage IV B-cell Lymphoma diagnosed 2 years ago, initially treated with Rituximab-Bendamustine, currently on rituximab maintenance therapy presented to the clinic for 2-week history of odynophagia and dysphagia. Physical exam was unremarkable. Labs showed WBC count of 2900 cells/uL with mild neutropenia of 1500 cells/uL and lymphopenia of 400 cells/uL (normal 0.7-4 k cells/uL). Esophagogastroduodenoscopy (EGD) showed multiple large ulcers in the mid-esophagus measuring 5-6 cm. Biopsies demonstrated reactive squamous epithelial changes and granulation tissue with no evidence of viral infection or malignancy. Testing for CMV, HSV, AFB, bacterial and fungal cultures, were negative. The patient was initially given a trial of PPI and empiric antiviral therapy with Valganciclovir for a week with no subjective improvement in symptoms. Repeat EGD showed mid-esophageal ulcers, unchanged from prior exam with negative biopsies. Repeat labs showed normal white count with Lymphopenia of 400 cells/uL. At this juncture, the patient was thought to have esophageal ulcers secondary to immunosuppression and rituximab was stopped. He was started on prednisone 20mg twice a day. He reported symptomatic relief within a week. EGD after 4 weeks showed healing ulcers. The patient is currently being tapered off the steroids. Idiopathic giant esophageal ulcers are rare and occur in the distal half of esophagus. Pathogenesis of these ulcers is unclear. Literature review shows few cases of idiopathic ulcers in AIDS and transplant patients that respond to steroid therapy with endoscopically documented healing. Alterations in the immune system leading to leukopenia may be the underlying mechanism for these ulcers. Even though our patient did not have a significant leukopenia, he did have lymphopenia. Rituximab may have induced an imbalance between various lymphocyte subpopulations and played a role in the pathogenesis of these ulcers. Steroid therapy and discontinuation of rituximab may have restored the immune balance. In conclusion, rituximab was the likely cause of multiple esophageal ulcers in our patient, and they responded to steroids.

OsmoPrep-associated Gastritis: A Histopathologic Mimic of Iron Pill Gastritis and Mucosal Calcinosis.

We have identified 8 cases of gastritis characterized by the presence of purple to black granular deposits in the superficial mucosa associated with marked reactive epithelial changes. In each case, the patient had taken OsmoPrep, a tablet form of sodium phosphate used for bowel preparation just before upper endoscopy and had undergone concurrent colonoscopy. Endoscopic findings ranged from normal gastric mucosa to severe inflammation, congestion, and friability. No other gastrointestinal sites were noted to contain the deposits or show similar mucosal injury. On initial histologic review, the deposits raised the differential diagnosis of elemental iron and mucosal calcinosis. However, none of the patients was noted to be taking iron supplements, and none had a history of renal disease or other cause of calcium dysmetabolism. Histochemical stains revealed the deposits were negative on Perls' iron stain (8/8 cases), positive on von Kossa stain (7/8 cases), and negative on Alizarin Red stain (8/8 cases)-a histochemical profile compatible with sodium phosphate but inconsistent with mucosal calcium. A crushed OsmoPrep tablet was subjected to processing and demonstrated similar histologic features and histochemical profile. In addition, biopsies of 20 consecutive patients who did not take OsmoPrep and who underwent concurrent endoscopy and colonoscopy were reviewed, and no deposits with similar histochemical profile were identified. In summary, we have characterized a unique form of gastritis associated with OsmoPrep use. Attention to clinical history and use of a select panel of histochemical stains allow for accurate diagnosis.

Acute Perforating Diverticulitis Associated with Active Ulcerative Colitis: Yes, It Does Occur

A 79-year-old female with a past medical history of UC presented with persistent watery diarrhea, abdominal pain, nausea, vomiting, and low-grade fever. She had originally presented 1.5 years prior with persistent hematochezia prompting colonoscopy which revealed congestion, erosions, erythema, friability, granularity and loss of vascularity extending in a continuous and circumferential pattern from the anus to the sigmoid colon. Numerous small and large-mouthed diverticula were found in the sigmoid colon and in the descending colon. Rectosigmoid biopsy revealed crypt distortion with increased lymphoplasmacytic and neutrophilic inflammatory infiltrate in the lamina propria and associated cryptitis, crypt abscesses, and reactive epithelial cell changes consistent with a diagnosis of UC. Over the next 1.5 years she intermittently tolerated combinations of 5-aminosalicylic acid preparations (5-ASA) and steroid suppositories and enemas with concomitant oral 5-ASA therapies. However she eventually developed steroid-dependent UC. Given persistent side effects of chronic steroid therapy biologic therapy with infliximab was started approximately one week prior to presentation. On admission to hospital, she was started on broad-spectrum antibiotics and intravenous steroids. With a negative infectious workup, she was continued on an accelerated infliximab program. This was complicated by the development of Clostridium Difficile colitis, requiring oral vancomycin therapy. She subsequently developed worsening abdominal pain prompting computed-tomography evaluation which revealed colitis with increased wall thickening and pericolonic inflammation along the descending colon with an associated droplet of extraluminal air and rim-enhancing fluid in the left paracolic gutter compatible with perforation. She underwent emergent exploratory laparotomy with identification of a descending colonic perforation resulting in subtotal colectomy with end ileostomy. Her post-op course was complicated by multiple pelvic fluid collections documented on serial imaging requiring drainage and growth of Vancomycin-Resistant Enteroccocus. Microscopic surgical pathology showed chronic UC associated with extensive colonic diverticulosis with acute perforative diverticulitis, subserosal abscesses and acute purulent serositis. The inflammation of UC was limited to the deep submucosa. There was no dysplasia, granulomata, or viral inclusions present.