リニア型EUSを用いた頸胸腹3領域リンパ節検索

Diagnosis of Lymph Node Metastasis in the Cervical, Mediastinal, and Abdominal Cavities Using Linear Endoscopic Ultrasound

要旨●食道表在癌に対してESDの適応を拡大する際には，転移のリスクがある腹部・縦隔・頸部の3領域リンパ節の系統的な検索が必要である．リニア型EUSはコンベックス型より食道壁および近傍の描出に優れ，食道癌の検索に適している．消化管に対して長軸方向の画像が得られるため，噴門部や頸胸境界部の検索にも有効である．EUSによる検索は，周囲臓器の解剖学的位置関係を把握することが大切で，各位置でメルクマールとしている臓器を確認しながら周囲を検索する．EUSは，リンパ節の形態や内部構造を吟味できることから，リンパ節転移診断の質を向上させる効果がある．EUSによる3領域リンパ節の検索は，食道表在癌のESD適応拡大症例の転移・再発の早期診断につながると考えられる．

　To extend the application of ESD to superficial cancers of the esophagus, it is necessary to systematically examine the lymph nodes in the 3 fields of cervical, mediastinal, and abdominal cavities associated with a risk of metastasis. Linear endoscopic ultrasound（EUS）is superior to convex（EUS）in the depiction of the esophageal wall and its neighboring organs and is suitable for the detection of esophageal cancer. Because a longitudinal image is provided for the digestive tract, it is also effective for the retrieval of the cardiac part and the thoraco-cervical boundary. It is essential to understand the anatomical relationship of the esophagus with its surrounding organs and examine the surrounding area while confirming the index organs at each position. Because EUS can closely examine a form and internal echo pattern, it improves the quality of the diagnosis of lymph node metastasis. In addition, the systematic examination of the lymph nodes in these 3 fields leads to the early detection of metastasis and the recurrence of superficial esophageal cancer, thus extending the application of ESD.