[707] Increased Intraepithelial Eosinophils in Patients Undergoing Photodynamic Therapy

VL Owens, TC Smyrk, KK Wang. Mayo Clinic, Rochester, MN

Background: Markedly increased esophageal intraepithelial eosinophils (IEE) are usually associated with the clinicopathologic syndrome of eosinophilic esophagitis (EE), a syndrome dominated by dysphagia. We noted markedly increased IEE in some patients undergoing photodynamic therapy (PDT) for esophageal dysplasia/neoplasia and were surprised to learn that the patients did not have symptoms or endoscopic features of EE. We proceeded to review the esophageal findings in our entire cohort of patients undergoing PDT.
Design: 385 patients underwent PDT between the years 1991-2009. The pathology reports from all endoscopic biopsies were reviewed for increased IEE. 187 patients had at least some esophageal eosinophils, and 17 patients had biopsies read as having "numerous/many" eosinophils or more than 20 IEE/high power field. We reviewed all endoscopic biopsies from these 17 patients and assessed the maximum density of IEE/HPF, presence or absence of degranulation, basal zone thickness, papillary height, spongiosis, and density of eosinophils in the stomach. The patient's date of PDT was correlated with symptoms and endoscopic findings at the time of biopsy.
Results: In 14/17 patients, there was a temporal relationship between increased IEE and PDT. The number of days after PDT to the first significant increase in IEE (≥20 eosinophils/HPF) ranged from 83-692 days. The highest peak density of IEE ranged from 30-200/HPF (mean=96). In 6/14 biopsies, the highest peak density was in the first post-PDT biopsy, and in many patients increased IEE persisted for years. The majority of cases showed eosinophilic degranulation, spongiosis, increased papillary height, and basal zone thickening. In most cases, eosinophil density was greatest in the basal 2/3's of the squamous epithelium. All patients had at least some gastric eosinophils, with densities ranging from 1-75/HPF (mean=26). No patients had endoscopic findings of EE. One patient had dysphagia, but had a post-therapy related stricture; another patient complained of rare episodes of dysphagia.
Conclusions: 14 of 385 patients undergoing PDT developed increased IEE, but they did not have endoscopic findings or symptoms of EE. There may be subtle histologic clues to the diagnosis of PDT-related IEE (basally distributed eosinophils; gastric involvement by eosinophils). The fact that eosinophils can be quite numerous and are degranulated in PDT patients without dysphagia suggests that other effectors play a role in the development of dysphagia in EE.
Category: Gastrointestinal

Monday, March 22, 2010 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 103, Monday Morning


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