門脈輪状膵を伴う早期胃癌に対して腹腔鏡下幽門側胃切除術を施行した1例

A case of early-stage gastric cancer combined with portal annular pancreas treated by laparoscopic distal gastrectomy

◆要旨：症例は62歳の女性で，胃体下部の早期胃癌の診断で手術を施行した．膵上縁のリンパ節郭清で，総肝動脈頭側に広い範囲で膵実質を認めた．術前には門脈輪状膵の存在が念頭になく，膵実質を#8aリンパ節と捉えて郭清を進めていたが，途中で色調の違いにより膵実質と認識できた．膵実質の損傷はなく，腹腔鏡下幽門側胃切除術を施行した．CT画像を確認すると，門脈は完全に膵実質で包まれており，門脈輪状膵の所見であった．これまでに門脈輪状膵を伴う症例に対する胃癌手術の報告はないが，その存在は膵上縁リンパ節郭清の際に膵損傷に至る危険性を有すると考えられるため，その経験を報告する．

　We report a case of early-stage gastric cancer combined with portal annular pancreas （PAP） treated by laparoscopic distal gastrectomy. A 62-year-old woman with a diagnosis of early-stage gastric cancer in the lower stomach underwent surgery. During the suprapancreatic nodal dissection, a large amount of pancreatic parenchyma was found in the cranial side of the common hepatic artery. We did not recognize the presence of PAP before surgery; thus, we misunderstood the pancreatic parenchyma as lymph node #8a. During the dissection of node #8a, the tissue was recognized not as the node but as the pancreatic parenchyma based on its differences in color. Laparoscopic distal gastrectomy was performed without any injuries to the pancreas. Retrospectively, computed tomography showed that the portal vein was completely surrounded by pancreatic parenchyma, which was a finding of PAP. Although there have been no reports of surgery performed for gastric cancer with PAP, the presence of PAP confers a risk of pancreatic injury during suprapancreatic nodal dissection.