幽門下領域に異所性膵を併存した胃癌に対して腹腔鏡下幽門側胃切除を施行した2例

Laparoscopic gastrectomy for gastric cancer with ectopic pancreas in infrapyloric area

◆要旨：腹腔鏡下胃切除術において，十二指腸球部大彎側から発生した異所性膵の2例を経験した．異所性膵は，幽門下動静脈の背側に位置しており正常膵との連続は認めなかった．組織学的には，十二指腸の固有筋層から漿膜外の脂肪組織内に存在する膵組織であり，外分泌腺とランゲルハンス島，導管が確認された．1例は術前CT検査で同定困難であり，術中の膵頭部前面の剝離層の同定に難渋し，いずれの症例も再建方法の変更が必要であった．幽門下領域に異所性膵が存在する可能性を理解しておくことは，安全に幽門下領域の郭清および再建を行うために重要であると考えられた．

　We report two cases of gastric cancer with ectopic pancreas detected during laparoscopic gastrectomy. In both cases, ectopic pancreas was located on the greater curvature of the first portion of the duodenum and was 20-30 mm in diameter. Pathological findings revealed that ectopic pancreas arose from the duodenal muscularis propria and comprised of acinar cells, islets of Langerhans, and ducts. If ectopic pancreas has similar exocrine secretion function, injury of ectopic pancreas may cause postoperative pancreatic fistula. Ectopic pancreas was detectable by computed tomography （CT） in only one of two cases. In both cases, ectopic pancreas in the infrapyloric area increased the technical difficulty of lymph node dissection and required a conversion from Billroth I reconstruction to Roux-en-Y reconstruction. For a safe lymph node dissection in the infrapylolic area, awareness of ectopic pancreas is necessary. CT may be useful for preoperative diagnosis of the ectopic pancreas.