3年以上の長期生存が得られた小膵癌の1例

A Patient with Small Pancreatic Cancer Who Survived More Than Three Years, Report of a Case

要旨　3年以上の長期生存の得られた腫瘍径1cm以下の小膵癌の1例を報告した．腫瘍の拾い上げには腹部超音波検査が有効であった．腫瘍の存在診断，鑑別診断にはERCPと超音波内視鏡が極めて有用で，小膵癌の診断はこの3つの診断法を中心に展開すべきものと考えられた．また，自験の小膵癌例の分析から，膵癌，特に小膵癌は3つの型，充実型，囊胞型，管内型に分類されることが判明した．早期診断には，これら各々の型に合った診断法を適宜選択すべきであると考えられた．

　A 57-year-old woman was seen because of body weight loss and general fatigue. Laboratory findings were normal. Ultrasonography showed a hypoechoic mass, 12 mm in diameter, in the body of the pancreas. Conventional ERCP revealed stenosis of the main duct in the pacreatic body. Magnified ERCP showed tapering stenosis of the main duct and branch ducts. Enhanced CT and angiography, however, showed no abnormality. Endoscopic ultrasonogram (EUS) demonstrated a well defined tumor mass with no dilatation of the caudal pancreatic duct. The tumor mass was hypoechoic as a whole, and centrally echogenic by EUS. Distal pancreatectomy was performed.

　Histological examination revealed moderately differentiated tubular adenocarcinoma, 8 mm in diameter, within the pancreatic capsule. We experienced 21 cases of pancreatic cancer smaller than 2 cm, including this case, and 4 cases of pancreatic carcinoma in situ. Based on these experiences, a new classification of pancreatic duct cancer was proposed to make diagnosis in early stage. That includes 1) scirrhous invasion type, 2) intraductal spreading with mucin hypersecretion type, 3) intraductal spreading without mucin hypersecretion type.

　It is necessary, we think, to make a judicious choice among a variety of imaging modalities and biopsy procedures according to this classification.