Methylene Blue Solution-induced Acute Esophageal Mucosal Injury: First Case Report / 대한소화기내시경학회지

Methylene blue (MB) based chromoendoscopy has been used for more than a decade to increase detection rates of specialized intestinal metaplasia, dysplasia, and esophageal adenocarcinoma. It is also used to detect anastomotic leakage after an operation. A 67-year-old man with no previous medical problems had complaints of jaundice and weight loss for 2 months. He was diagnosed with a Klatskin tumor and was referred to our hospital. An initial esophagogastroduodenoscopy (EGD) was performed before the operation. No abnormality was observed in the esophagus. MB solution was infused via an L-tube to check for leakage in the anastomosis. Subepithelial hemorrhagic and edematous mucosal changes with friability and a bluish mucosal discoloration were noted 2 days later from the mid to lower esophagus on EGD. Nine months later, an EGD revealed an unremarkable esophageal mucosa. MB solution is considered safe; however, a large volume or high concentration of MB solution might be harmful.

Endoscopic Resection of Early Gastric Cancer

Endoscopic mucosal resection (EMR) has been accepted as one of the standard treatments of early gastric cancer (EGC) with a negligible risk of lymph node metastasis. EMR is similar to surgery in efficacy but less invasive and more cost-effective. And it allows accurate histological staging of the tumor, which is critical in deciding whether additional treatment is necessary. Standard indications for EMR of EGC include differentiated elevated cancer less than 2 cm in size and depressed cancer without ulceration less than 1 cm in size. Recently, expanded indication has been proposed in Japan to cover other lesions with a negligible risk of lymph node metastasis, which include larger lesions and lesions with ulceration. With the development of endoscopic submucosal dissection (ESD), en bloc resection of larger and even ulcerative lesion is possible. However, the lack of long-term data makes it difficult to widely accept expanded indication. More long-term studies about therapeutic outcomes are needed to fully bolster the safety and establish correct therapeutic role of ESD in treatment of EGC.