Advanced pathology under squamous epithelium on initial EMR specimens in patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma: implications for surveillance and endotherapy management.

摘要

BACKGROUND: Prior studies report the presence of buried Barrett's epithelium under squamous mucosa after endoscopic ablative therapies for Barrett's esophagus (BE) with high-grade dysplasia (HGD) or intramucosal carcinoma (IMC). However, there still exists significant controversy about whether these glands represent a neoablative phenomenon or predate endoscopic therapy. OBJECTIVE: To determine the prevalence of buried BE underneath squamous epithelium on initial mucosectomy specimens for complete Barrett's eradication EMR (CBE-EMR) for BE with HGD or IMC. DESIGN: Retrospective double-blinded review. SETTING: A tertiary-care academic referral center. PATIENTS AND METHODS: Histopathology slides of all initial mucosectomy specimens for all patients who underwent CBE-EMR for BE with HGD or IMC at our center between August 2003 and February 2008 were reviewed retrospectively in a double-blinded fashion by 2 expert GI pathologists. None of the patients had undergone prior endoscopic ablative therapy for dysplastic BE. MAIN OUTCOME MEASUREMENTS: The prevalence of buried BE underneath squamous epithelium in initial mucosectomy specimens from CBE-EMR for BE with HGD or IMC. RESULTS: A total of 47 patients' initial mucosectomy slides were reviewed. The presence of Barrett's epithelium underneath the squamous resection margin (Z line) was identified in 13 of 47 patients (28%) at initial mucosectomy. The linear distance of the Barrett's epithelium from the resection's squamous margin ranged from 0.8 to 5.6 mm (mean 2.3 mm and median 1.9 mm). Histopathology revealed nondysplastic buried BE in 3 patients, HGD in 9 patients, and IMC in 1 patient. Thus, 10 of 13 patients (21% of 47 total) had buried glands with advanced pathology (HGD or IMC), whereas 3 of 13 (6% of 47 total) had specialized intestinal metaplasia without dysplasia. LIMITATIONS: A single-center, modest study population size. CONCLUSIONS: Our results revealed a significant prevalence of buried Barrett's epithelium with or without dysplasia under squamous mucosa (squamocolumnar junction) on initial mucosectomy specimens. Given the neoplastic potential of BE, the presence of these subsquamous BE glands may affect the extent and adequacy of mucosal resection margins. Based on these findings, surveillance biopsies and ablative therapy should extend to 1 cm proximal to the endoscopically determined squamocolumnar junction.