Eosinophilic esophagitis and esophageal granular cell tumor. An unexpected association

Esophageal granular cell tumors (GCTs) are rare. Eosinophilic esophagitis (EoE) is an immune-mediated disease characterized by esophageal eosinophilia despite proton pump inhibitor (PPI) therapy. Given that GCTs occur at sites of scarring and inflammation, we sought to determine the prevalence of EoE in patients with esophageal GCTs. Our center's pathology database was searched for GCT specimens from 1995 to 2014. Slides were blindly rereviewed. GCTs were scored for atypical cytological features. Presence and number of eosinophils in the tumor and the surrounding esophageal epithelium and any EoE features were recorded. Medical records were reviewed. From >30,000 esophageal cases, 23 esophageal GCTs were identified, with 18 available for review (16 adult, 2 pediatric). Median patient age was 38.7 years. Four adults had esophageal intraepithelial eosinophilia (peak 38 to 68 eosinophils/ high power field [HPF]); 2 confirmed to have EoE, 1 with PPI-responsive esophageal eosinophilia, and 1 had not received PPI therapy. Both pediatric cases had confirmed EoE (peak 24 and 34 eosinophils/HPF). In total, 12/18 GCTs had intratumoral eosinophilia (peak 1 to 16 eosinophils/HPF). All 6 cases with esophageal eosinophilia had intratumoral eosinophilia. Two GCTs displayed atypical cytologic features. Esophageal eosinophilia was present in 25% of adult and 100% of pediatric GCTs, the majority confirmed to have EoE. Overall, 67% of cases had intratumoral eosinophilia and 2 had atypical features. On the basis of these findings, we propose evaluating surrounding tissue for eosinophilia when esophageal GCT is diagnosed, and adding GCT as a potential complication of untreated EoE. Research for an immunologic link between EoE and esophageal GCTs is needed.