6951 Moderately differentiated adenocarcinoma complicating an ablated segment of esophageal columnar lined epithelium using argon plasma coagulation.

Columnar lined epithelium (CLE) is a well recognized complication of gastroesophageal reflux disease (GERD) which carries a significant risk of malignant transformation. Various therapeutic modalities have been used to ablate CLE, in an attempt to abolish the risk of malignancy, such as bipolar electrocoagulation, argon plasma coagulation (APC) and photodynamic therapy. There has been a concern that regeneration of squamous epithelium may not protect patients from the occurence of adenocarcinoma. We report the first case of moderately differentiated adenocarcinoma arising in APC regenrated squamous epithelium six months after complete ablation. Case Report:A 69 year-old man with a history of GERD complicated by CLE of ten years duration was found to have low grade dysplasia at surveillance endoscopy. The patient elected to undergo APC ablation therapy in addition to enhanced surveillance. His past medical history was significant of hypertension and ischemic heart disease. His medication included lansoprazole, atenolol and aspirin. He denied alcohol use and gave up smoking twenty years ago. His family history was significant for mother dying of esophageal carcinoma and a sister having GERD and CLE. Physical examination was unremarkable. He underwent endoscopy which revealed a 6 cm segment of CLE. Post biopsies, the entire segment of CLE was treated with APC using ERBE set at 35-40 Watts and gas flow at 0.4 liter/min. Biopsies confirmed low grade dysplasia. Subsequently he underwent three sessions of APC at two months intervals resulting in near complete regression of his CLE. A surveillance endoscopy six months later revealed an ablated CLE with a few new 2-3 mm islands of CLE surrounded by squamous epithelium. At 33 cm, the site of the pre-treatment squamocolumnar junction, there was a new nodular 3 mm area of CLE. Biopsies showed moderately differentiated adenocarcinoma. Patient underwent endoscopic ultrasonography which revealed a 3 mm nodule with two adjacentlymph nodes suggestive of malignant involvement. Conclusion:We described a case of long segment of CLE ablated by APC in which a malignant transformation was detected on subsequent surveillance endoscopy. This case indicates that ablation of CLE does not necessarily abolish the risk of malignancy. When APC ablation is contemplated in the setting of low grade dysplasia, frequent endoscopic follow up is essential.We recommend that surveillance endoscopy with biopsies should be every six months.