Gastric dysplasia-like epithelial atypia associated with chemoradiotherapyfor esophageal cancer: A clinicopathologic and immunohistochemical study of 15 cases

Preoperative chemotherapy combined with radio-therapy (chemrad) is a common type of neoadjuvant treatment for esophageal adenocarcinoma or squamous ce ll carcinoma. The purpose of this study was to describe the clinical, histo logic, proliferative (MIB-1), and oncogenetic (p53) features of 15 patients with gastric dysplasia-like epithelial atypical changes associated with pr eoperative chemrad for esophageal cancer. Two of these cases were initially misinterpreted as dysplasia, which led to partial gastrectomy, The finding s were compared with 12 age- and sex-matched patients with known gastric dy splasia. Cases with gastric dysplasia-like epithelial atypia were significa ntly associated with a fiat gross appearance, a patchy distribution, foveol ar and gland involvement, surface maturation, an open nuclear chromatin pat tern with prominent nucleoli, retention of nuclear polarity, mitoses confin ed to the pits, lack of atypical mitoses, cytoplasmic hypereosinophila and/ or vacuolization, a lack of association with intestinal metaplasia, and fin ally, irregular glandular microcystic change, in comparison to the dysplasi a controls, Furthermore, the study cases showed MIB-1 positivity restricted to the deep foveolar epithelium and an absence of p53 staining in 14 of 15 cases, in contrast to the dysplasia controls, in which MIB-1 stained both the deep and superficial foveolar epithelium and surface epithelium, and p5 3 was positive in all cases (100%), m summary, a number of histologic and I mmunohistochemical features may distinguish gastric dysplasia-like epitheli al atypia associated with chemrad for esophageal cancer from true dysplasia . Pathologists should be aware of this entity and its histologic and immuno histochemical features to avoid misinterpretation and prevent unnecessary t reatment.