Bizarre stromal cells in the esophagus: report of 2 cases and literature review.

A significant mimicker of malignancy in the esophagus is the presence of atypical/bizarre stromal cells (BSCs). Two patients, a 60-year-old woman and a 59-year-old man, with esophageal polyps at the gastroesophageal junction showed highly atypical/bizarre cells in the polyps' stroma. BSCs were admixed with inflammatory cells and had large atypical nuclei, prominent nucleoli, and variably abundant amphophilic cytoplasm. Immunohistochemical studies showed that BSCs expressed vimentin whereas S-100, CD68, HMB45, CD45, Pan-cytokeratin, CK5/6, p63, CD10, EMA, MART-1, desmin, smooth muscle actin, CD31, CD34, and CMV were negative. Ki-67 showed low proliferative rate (less than 1% positivity). No evidence of intracellular mucin was found after histochemical stains (AB/PAS and mucicarmine). Follow-up endoscopic mucosal resection was available in both cases and showed benign esophageal mucosa and submucosa with disappearance, in one case, or marked decrease of BSCs. Esophageal BSCs reports in the literature invariably locate them in distal esophagus polyps or masses. Awareness of BSCs, of their location and associations, may help to prevent misdiagnosis of malignancy. The literature of esophageal BSCs is reviewed and the approach to this abnormality is discussed.