FDG PET/CT in eosinophilic esophagitis

Monitoring and modulating the trajectory of eosinophilic esophagitis

Current treatments of eosinophilic esophagitis (EoE) aim to eliminate esophageal mucosal inflammation and attenuate, stabilize, or reverse stricture formation. However, our ability to study the long-term course of esophageal strictures in patients with EoE is hampered by the short-term existence of this disease. It is unclear to what degree of control of inflammation is needed to prevent stricture formation. Additionally, identified phenotypes of EoE may ultimately dictate different levels of concern and time intervals for developing fibrosis. Currently, multiple methods are used to monitor patients' disease progression to fibrosis, as symptoms alone do not correlate with disease activity. Endoscopic findings and mucosal histology are used to monitor disease activity, but these focus on improvements in inflammation with inconsistent evaluation of underlying fibrosis. The use of functional lumen impedance planimetry, barium esophagraphy, and endoscopic ultrasound continues to expand in EoE. The rapid advancements in EoE have led to an armamentarium of measuring tools and therapies that holistically characterize disease severity and response to therapy. Nevertheless, our ability to evaluate gross esophageal fibrosis and stricture formation from a transmural rather than mucosal view should be a focus of future investigations because it is essential to monitoring and modulating the trajectory of EoE.

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

BACKGROUND

Eosinophilic 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 biopsy specimens from patients with EoE.

OBJECTIVE

We hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE.

METHODS

We evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-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.

RESULTS

EoE33 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 pathologic changes in vivo. EoE33 mice were responsive to steroids.

CONCLUSIONS

IL-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.

FDG PET/CT in a Case of Esophageal Extranodal NK/T-Cell Lymphoma, Nasal Type

ABSTRACT

Lymphoma involving the esophagus is rare. We describe FDG PET/CT findings in a case of extranodal NK/T-cell lymphoma, nasal type involving the larynx, hypopharynx, and cervical and upper thoracic esophagus. The esophageal tumor showed segmentally increased FDG uptake mimicking esophagitis. This case indicates that esophageal lymphoma should be included in the differential diagnosis of the hypermetabolic esophageal diseases.

FDG PET/CT in a Case of Diffuse Esophageal Adenocarcinoma

ABSTRACT

Esophageal cancer usually shows focal intense FDG uptake on FDG PET. Diffuse FDG uptake pattern of the esophageal cancer has been rarely reported. We describe FDG PET/CT findings in a case of esophageal adenocarcinoma showing diffusely intense FDG uptake mimicking esophagitis.

A case of eosinophilic gastroenteritis with high PET-CT accumulation treated by P-CAB

Eosinophilic gastroenteritis (EGE) can present findings on computed tomography (CT) images that resemble malignant tumors. EGE is generally treated with systemic oral steroid administration, which is reportedly effective in relieving symptoms at least temporarily. Here, we report a case of EGE that mimicked malignant lymphoma in a gastroduodenal lesion, in which treatment with a potassium-competitive acid blocker without systemic oral steroid administration relieved the symptoms and reversed the initial image findings. A 56-year-old woman became aware of discomfort in her epigastric region, which gradually worsened. This case showed antroduodenal wall thickness, which mimicked a malignant lymphoma with increased F-18 fluorodeoxyglucose (FDG) uptake by positron emission tomography/computed tomography (PET/CT). An upper gastrointestinal endoscopy revealed protruding erosions in the antrum and severe edematous changes in the duodenum. Extensibility of the normal gastric wall by insufflation also occurred. However, an abdominal ultrasound indicated wall thickening with a preserved wall structure. Histological examinations showed a large amount of eosinophil infiltration, mainly in the gastroduodenal mucosa, without malignant cells. Thus, we made a final diagnosis of EGE. The patient was then administered 20 mg vonoprazan fumarate per day because she refused steroid treatment and because the pathological lesion was also localized from the duodenum to the antrum. After 3 weeks of potassium-competitive acid blocker treatment, her symptoms were alleviated, and the degree and extent of thickening of the gastroduodenal wall in upper gastrointestinal endoscopy and ultrasonographic image findings had remarkably improved.

Cowden Syndrome Detected by FDG PET/CT in an Endometrial Cancer Patient

Cowden syndrome (CS) is a rare autosomal dominant disorder characterized by multiple hamartomas in various tissues and cancers (breast, thyroid, and endometrium). We report CS of the esophagus and gastrointestinal tract that was incidentally detected by positron emission tomography/computed tomography (PET/CT) at postoperative surveillance in an endometrial cancer patient. PET/CT showed mildly increased FDG uptake along the entire esophagus and stomach. Upper GI endoscopy and histologic examination revealed glycogenic acanthosis of the esophagus and several hundred gastric polyps. In our case, increased FDG uptake of the esophageal wall contributed to the diagnosis of CS.

Advances in clinical management of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic immune/antigen-mediated clinicopathologic condition that has become an increasingly important cause of upper gastrointestinal morbidity in adults and children over the past 2 decades. It is diagnosed based on symptoms of esophageal dysfunction, the presence of at least 15 eosinophils/high-power field in esophageal biopsy specimens, and exclusion of competing causes of esophageal eosinophilia, including proton pump inhibitor-responsive esophageal eosinophilia. We review what we have recently learned about the clinical aspects of EoE, discussing the clinical, endoscopic, and histological features of EoE in adults and children. We explain the current diagnostic criteria and challenges to diagnosis, including the role of gastroesophageal reflux disease and proton pump inhibitor-responsive esophageal eosinophilia. It is also important to consider the epidemiology of EoE (with a current incidence of 1 new case per 10,000 per year and prevalence of 0.5 to 1 case per 1000 per year) and disease progression. We review the main treatment approaches and new treatment options; EoE can be treated with topical corticosteroids, such as fluticasone and budesonide, or dietary strategies, such as amino acid-based formulas, allergy test-directed elimination diets, and nondirected empiric elimination diets. Endoscopic dilation has also become an important tool for treatment of fibrostenotic complications of EoE. There are a number of unresolved issues in EoE, including phenotypes, optimal treatment end points, the role of maintenance therapy, and treatment of refractory EoE. The care of patients with EoE and the study of the disease span many disciplines; EoE is ideally managed by a multidisciplinary team of gastroenterologists, allergists, pathologists, and dieticians.