右側大腸に好発する腫瘍の内視鏡的特徴―LST

Endoscopic and Clinicopathologial Features of Laterally Spreading Tumors in the Right Colon

要旨　当院において10年間で治療された側方発育型腫瘍（laterally spreading tumor ; LST）1,337症例（1,541病変）に対して，臨床病理学的特徴（性別，年齢，腫瘍径，病理）を部位・亜分類別に比較することにより，右側結腸LSTの特徴を明らかにした．右側結腸LSTは，（1）全LSTの60.9％を占める，（2）性差は認めない，（3）高齢者に多い，（4）LST-NGが多い，（5）平均腫瘍径は他部位と比較すると小さくSM癌率も低い，という特徴があった．

　The aim of this study was to evaluate the clinicopathologial features of LSTs（laterally spreading tumors）focusing on their locations.

　In a retrospective review of the colonoscopy database（April 2001 to Jun 2011）at the Showa University Northern Yokohama Hospital, we selected LST cases that underwent subsequent endoscopic or surgical resection. We evaluated clinicopathological features（gender, age, LSTs subtype, size, rate of submucosal invasion）focusing on their locations. For analysis, the locations were divided into three groups ; right colon, left colon and rectum.

　As a result, over 60％of LSTs were found in the right colon. LSTs in the right colon showed lesser tumor size and lower rate of submucosal invasion than those in other locations. In gender, size of tumor, and LSTs subtype, there was significant difference among cecum, ascending colon, and transverse colon.