大内田 祐一 ¹, 堀井 勝彦 ², 岡 博子³, 横田 重樹¹, 櫻田 啓子¹, 嶋 三恵子¹, 中井 隆志³, 川崎 靖子³, 山崎 修², 井上 健⁴

Yuichi OUCHIDA¹, Katsuhiko HORII², Hiroko OKA³, Shigeki YOKOTA¹, Keiko SAKURADA¹, Mieko SHIMA¹, Takashi NAKAI³, Yasuko KAWASAKI³, Osamu YAMAZAKI ², Takeshi INOUE⁴

¹大阪市立総合医療センター中央臨床検査部, ²大阪市立総合医療センター消化器外科, ³大阪市立総合医療センター消化器内科, ⁴大阪市立総合医療センター病理部

¹Central Clinical Laboratory, Osaka City General Hospital, ²Department of Surgery, Osaka City General Hospital, ³Department of Gastroenterology, Osaka City General Hospital, ⁴Department of Pathology, Osaka City General Hospital

キーワード : cystic tumor of the pancreas, IPMN, MCN

当院消化器外科で切除された膵嚢胞性腫瘍32 例について, その臨床像, 画像所見, 特に超音波像と病理所見を検討した. 32 例の内訳は膵管内乳頭粘液性腫瘍(IPMN) 26 例と粘液性嚢胞腫瘍(MCN) 6 例. IPMN は主膵管型8 例, 分枝型18 例で, 腺癌16 例, 境界病変1 例, 腺腫9 例, 平均年齢65.8 歳, 高齢男性の膵頭部に多く見られた. MCN は腺癌3 例, 腺腫3 例, 平均年齢55.0 歳, 全例女性で膵体尾部に見られた. IPMN では分枝膵管拡張を伴ったものは多房性嚢胞像を呈し, 壁在結節像を認めた20 例中15 例ならびに主膵管径が6 mm以上の13 例中12 例が腺癌もしくは境界病変であった. MCN では単房性は1 例のみで残りの5 例は多房性で共通の被膜像で囲まれた形態を示した. 壁在結節は, 6 例中4 例に認められ, その内3 例が腺癌で, 1 例は壊死組織であった. 膵嚢胞性腫瘍では, 壁在結節像の有無が良悪性の鑑別に重要な所見であり, 加えてIPMN では6 mm以上の主膵管拡張は癌の存在を強く示唆する所見であった.

We carried out transabdominal ultrasonography and other imaging studies on 32 patients with cystic tumors of the pancreas. All subjects had undergone surgical treatment that was confirmed histologically. Twenty-six patients had intraductal papillary mucinous neoplasms (IPMNs). The lesions were main duct type in 8 patients and branch duct type in 18 patients; 6 patients had mucinous cystic neoplasms (MCN). Sixteen of the patients with intraductal papillary mucinous neoplasms had adenocarcinomas, 1 had a borderline lesion, and 9 had adenomas. Intraductal papillary mucinous neoplasms were often found in the head of the pancreas in older men (mean age, 65.8 years). Three of the patients with mucinous cystic neoplasms had adenocarcinomas, and 3 had adenomas, all found in the body and ⁄or tail of the pancreas of women (mean age, 55.0 years). Intraductal papillary mucinous neoplasms with branch duct dilatation were associated with multilocular cysts. Fifteen of 20 patients with mural nodules and 12 of 13 patients with a main pancreatic duct at least 6 mm in diameter had adenocarcinomas or borderline lesions. A unilocular cyst was observed in 1 of the patients with mucinous cystic neoplasms; multilocular cysts enclosed in a common capsule were found in 6 of the others. Three of 4 patients with mural nodules had adenocarcinomas. Mural nodules in intraductal papillary mucinous neoplasms and mucinous cystic neoplasms or a main pancreatic duct 6 mm or more in diameter in intraductal papillary mucinous neoplasms were indicative of malignancy.