Role of brush cytology in the diagnosis of Barrett's esophagus: An analysis of eight cases

Blind esophageal brushing offers a safe and accurate method to monitor inflammation in children and young adults with eosinophilic esophagitis

Patients with eosinophilic esophagitis (EoE) require frequent evaluation of mucosal inflammation via endoscopy. Instead of endoscopy, mucosal evaluation in adults with esophageal cancer and candidiasis is achieved using a cytology brush inserted through a nasogastric tube (NGT). We conducted a prospective cross-sectional study in children and young adults scheduled for routine esophagogastroduodenoscopy (EGD) where in Phase 1, we performed esophageal brushing through the endoscope under direct visualization and in Phase 2, we inserted the brush through a Cortrak® NGT prior to endoscopy. Eosinophil-derived neurotoxin (EDN) measured by ELISA in the samples extracted from brushes was validated as the sensitive biomarker. We collected 209 esophageal brushing samples from 94 patients and we found that EDN in brushing samples collected via EGD or NGT was significantly higher in patients having active EoE (n = 81, mean EDN 381 mcg/mL) compared with patients having gastroesophageal reflux disease (n = 31, mean EDN 1.9 mcg/mL, P = 0.003), EoE in remission (n = 47, mean EDN 3.7 mcg/mL, P = 0.003), or no disease (n = 50, mean EDN 1.1 mcg/mL, P = 0.003). EDN at a concentration of ≥10 mcg/mL of brushing sample was found to accurately detect active EoE. NGT brushing did not cause any significant adverse effects. We concluded that blind esophageal brushing using an NGT is a fast, less invasive, safe, and well-tolerated technique compared with EGD to detect and monitor EoE inflammation using EDN as the sensitive biomarker.

Promising Modalities to Identify and Monitor Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an allergen-mediated condition characterized by symptoms of esophageal dysfunction and histologic evidence of intense eosinophilic inflammation involving the esophagus in the absence of overlapping conditions such as gastroesophageal reflux disease. Since the initial description as a distinct entity approximately 2 decades ago, there has been a remarkable increase in the recognition of this clinicopathologic entity. The current approach to diagnose and monitor EoE requires repeated esophagogastroduodenoscopies, with associated sedation/anesthesia, to visualize mucosal abnormalities, and to obtain multiple biopsy specimens for histologic assessment and to evaluate treatment response. Frequent esophagogastroduodenoscopies with multiple biopsies can increase the risk of procedural complications, place significant financial burden on families, and escalate health care costs. In addition, this burdensome approach may contribute toward delayed diagnosis and suboptimal monitoring, thereby increasing the likelihood of complications such as esophageal narrowing and stricture formation, which may require escalation of care including endoscopic interventions. Clinical progression and complications associated with EoE can be attenuated through early identification and optimal management. Therefore, developing reliable, safe, less-cumbersome, and cost-effective modalities for early diagnosis and effective monitoring of EoE is an area of active research. These efforts have been substantially supported by the development of new biomaterials, analytic methodologies, and the application of novel concepts. Herein, we summarize modalities that have shown promise to advance the diagnosis and monitoring of EoE and could improve the care of affected individuals and advance the field.

Prospective assessment of the diagnostic utility of esophageal brushings in adults with eosinophilic esophagitis

Patients with eosinophilic esophagitis (EoE) undergo multiple endoscopies with biopsy for both diagnosis and assessment of treatment response, which is inconvenient and costly. Brush cytology has been examined in Barrett's esophagus to reduce the need for repeated endoscopic biopsies. The aim of this pilot study was to evaluate the ability of brush cytology to detect mucosal eosinophilia in patients with EoE. This prospective study included adults with untreated and treated esophageal eosinophilia undergoing endoscopy at a tertiary care center. Patients received paired brushings and biopsies at the proximal and distal esophagus. A blinded pathologist quantified the number of eosinophils and epithelial cells per high-power field (hpf) on the cytology slides. The ratio of eosinophils/epithelial cells was used to normalize the cytology specimens for density of cells collected. The main outcome measures were sensitivity and specificity of brush cytology, and correlation between cytology and histology. Twenty-eight patients enrolled. The average age of the cohort was 37.7 ± 10.4 years; 75% of subjects were male. The sensitivity of cytology was 67-69% at the proximal esophagus and 70-72% at the distal esophagus. The specificity was 61-67% proximally and 70-75% distally. Histology was not significantly correlated with the max ratio of eosinophils/epithelial cells per hpf or the absolute number of eosinophils on cytology slides. Cytology using esophageal brushing has limited sensitivity and specificity for the detection of esophageal mucosal eosinophilia. The presence of exudates on endoscopy increased the detection of eosinophilia, which could make cytology useful in pediatric EoE, which often has a more exudative presentation. Diagnostic yield may improve with alternative acquisition techniques or the incorporation of eosinophil degranulation proteins.

Utility of liquid-based cytologic examination of distal esophageal brushings in the management of Barrett esophagus: a prospective study of 45 cases

INTRODUCTION

The goal of Barrett esophagus surveillance is to identify high-grade dysplasia (HGD) for eradication. Surveillance programs currently rely on limited histologic sampling; however, the role of cytology in this setting is not well studied.

MATERIALS AND METHODS

From December 1, 2011 to March 30, 2014, 45 patients underwent 4 circumferential brushings of the distal tubular esophagus followed by standard 4-quadrant biopsies. One ThinPrep slide and 1 Cellient cellblock (Hologic, Boxborough, Mass) were prepared. Six cytopathologists evaluated each for adequacy, intestinal metaplasia (IM) and dysplasia. Findings were classified using the traditional 5-tier system used for biopsies. A prospectively modified 3-tier cytologic classification was also tested: negative for HGD, indeterminate for HGD, and HGD. Sensitivity, specificity, and kappa values (interobserver agreement) for cytology were calculated.

RESULTS

Ten of 45 patients had nondiagnostic cytologies; none of whom had dysplasia on biopsy. Cytology had good sensitivity (82%) and specificity (88%) for identifying IM compared with biopsy with moderate interobserver agreement (pairwise average of Fleiss and Krippendorf kappa value = 0.589, 79% agreement). One case had IM on cytology not detected on histology. Six of 45 patients had dysplasia on biopsy including 1 intramucosal adenocarcinoma, 1 indeterminate for dysplasia, 2 high-grade dysplasias, and 2 low-grade dysplasias. A non-negative adequate cytology sample had a sensitivity of 100% and a specificity of 88% and 94% for the 5-tier and the 3-tier classification, respectively.

CONCLUSIONS

Cytology appears to have good sensitivity and specificity for diagnosis of HGD, and cytology may be poised to synergize with advances in other techniques for management of patients with Barrett esophagus. Improvements in brushing devices may help to decrease the nondiagnostic rate.

Role of cytopathology in the diagnosis and management of gastrointestinal tract cancers

Cytology of gastro-intestinal (GI) tract lesions can be used successfully to diagnose neoplastic and non-neoplastic conditions, especially when combined with biopsies. Cytologic evaluation is widely accepted as a cost-effective method that allows rapid interpretation and triaging of material. Technical advances over the years have allowed simultaneous visualization of abnormal tissue and procurement of needle aspirates, brushings and biopsies from mucosal and deeper seated lesions. Successful cytologic examination of the GI tract is highly dependent on the skill of the endoscopist, specimen preparation, the expertise of the pathologist, and the recognition of the limitations of cytology. This article reviews the key cytologic features of important GI tract lesions, differential diagnoses, and pitfalls, and addresses the advantages and limitations of different collection techniques.