胃と図８の十二指腸（Du）が拡張しているが，原因は図９と図１０で嚢胞性病変（※）による圧排（▲）の可能性が高い．その嚢胞性病変（※）は肝門部から図１６の十二指腸外側までで，一見先天性胆道拡張症に見えるが，図５〜図８の嚢胞壁（↑）は胆道拡張症にしては厚いことと，十二指腸を圧迫して閉塞を起こしている点（胆道拡張症では極めてまれ）は他の疾患を鑑別する必要がある．胆道拡張症に胆管炎を合併していると診断し経皮的ドレナージを施行したら黄色膿汁が排出され，腹痛と発熱は消失した．図Aの嚢胞造影で十二指腸との交通を示し，さらに嚢胞壁の蠕動を認めた（白矢印）．手術で十二指腸重複症が確認され切除した．病理： Duodenal duplication（enteric cyst）．

参考症例１（7mmスライス，胃重複症）：上腹部痛と腹部膨満感を主訴に来院した73歳男性の胃重複症．

参考症例２（5mmスライス，回腸末端重複症）：間欠的上腹部痛で来院した23歳男性の回腸末端の重複症（↑）．

文献考察１）：腸管重複症281例の部位別頻度（表１）
Radiographics. 1993 Sep;13(5):1063-80.
Gastrointestinal tract duplications: clinical, pathologic, etiologic, and radiologic considerations.
Macpherson RI.

Gastrointestinal tract duplications are uncommon congenital abnormalities. By definition, they are located in or adjacent to the wall of part of the gastrointestinal tract, have smooth muscle in their walls, and are lined by alimentary tract mucosa. The lining mucosa is not necessarily that of the adjacent segment of the gastrointestinal tract. The only clinically important ectopic tissues are gastric mucosa and pancreatic tissue. Although ectopic gastric mucosa is found in duplications at all levels of the gastrointestinal tract, it is most prevalent (43%) in esophageal duplications. Peptic ulcer within this ectopic tissue can account for unusual, often misleading symptoms. Ectopic pancreatic tissue is most common (37%) in gastric duplications and is associated with pancreatitis and elevated amylase levels. Detection of associated vertebral anomalies is a helpful clue in the radiographic diagnosis of duplications. Barium studies usually reveal an intraluminal, intramural, or extrinsic mass, and ultrasonography (US) demonstrates its cystic nature. When US findings are inconclusive, computed tomography can be used to show the true nature, location, and extent of the lesion, as well as associated vertebral anomalies and possible other duplications. Technetium-99m pertechnetate scintigraphy provides definitive evidence of a duplication when it contains ectopic gastric mucosa and is particularly useful for suspected esophageal, duodenal, and small bowel lesions.PMID: 8210590

文献考察２）：腸管重複症小児例73例の部位別頻度（表２）
J Pediatr Surg. 2003 May;38(5):740-4.
Gastrointestinal duplications.
Puligandla PS, Nguyen LT, St-Vil D, Flageole H, Bensoussan AL, Nguyen VH, Laberge JM.

BACKGROUND/PURPOSE: The aim of this study was to review the presentations of gastrointestinal duplication (GID) and to assess the influence of prenatal diagnosis on treatment. METHODS: Retrospective review of all GID at 2 pediatric hospitals from 1980-2002 was conducted. RESULTS: Seventy-three patients (M43:F30) were identified: 21 neonates, 28 infants (1 to 24 months), 15 children (1 to 10 years), 9 adolescents (>/=11 years). GID location by frequency was ileum (31.5%), ileocaecal valve (30.2%), duodenum (9.6%), stomach (8.2%), jejunum (8.2%), colon (6.8%), and rectum (5.5%). In neonates and infants, vomiting and distension were the most common presentations. Volvulus, caused by a duplication, occurred in 23.8% of neonates and caused the death of one neonate. Intussusception was identified in 10.9% of patients. In older children and adolescents, pain and vomiting were the most common associations. Six of these patients were being treated for Crohn's disease, with the diagnosis of duplication made at laparotomy. Eighteen patients had a prenatal diagnosis by ultrasound scan, with 77.2% of these asymptomatic after birth. Most prenatal diagnoses occurred after 1991 (77.8%). When comparing an earlier period (1980 to 1991; 29 patients) with the current (1992 to 2002; 44 patients), a greater proportion of the latter patients were asymptomatic (36.4 v 13.8%) and had a lower incidence of complications (volvulus/intussusception). CONCLUSIONS: GID can lead to life-threatening complications. Prenatal diagnosis should lead to expeditious postnatal investigation and treatment before the onset of symptoms or complications. GID in older children can mimic Crohn's disease. Laparoscopy/laparotomy should be considered in patients with atypical Crohn's disease or when the diagnosis of an intraabdominal mass is unclear. Copyright 2003 Elsevier Inc. All rights reserved.PMID: 12720184

文献考察３）：十二指腸重複症
【知っておくべき疾患　十二指腸】　十二指腸重複症
　 Author：野口剛(大分医科大学 第2外科), 内田雄三
　 Source：臨床消化器内科(0911-601X)15巻9号 Page1237-1242(2000.07)
要旨：消化管重複症は嚢胞状(球状：圧倒的に多い)あるいは管状を呈し, 全消化管のどの部位にも発生しうるが, 十二指腸に発生するものは少なく, 本邦文献では4.7%(奥田ら)と報告されている. 十二指腸重複症は十二指腸第1部, 第2部の内側(時には膵内)に発生するものが多く, 総胆管や膵管(多くは副膵管)と合流するものがある. 嚢胞内に胃粘膜を有するものでは, 嚢胞壁に潰瘍形成や出血がみられることがある. 超音波検査で上腹部の嚢胞性腫瘤が, 内鏡検査では粘膜下腫瘤の像がみられる. 血管造影, CT, MRIでは嚢胞壁の性状のみならず隣接臓器とのより明確な所見を得ることができる. 治療としては, 発癌の可能性もあるので切除が行われる. marsupializationは避けるべきである．

文献考察４）：十二指腸重複症，本邦報告例43例（表３）
十二指腸重複症の1例と本邦報告例の検討
　 Author：五井孝憲(福井医科大学 第1外科), 片山寛次, 広瀬和郎, 他
　 Source：日本外科学会雑誌(0301-4894)96巻6号 Page399-401(1995.06)