十二指腸乳頭部癌の診断―各種画像診断能の比較

Preoperative Staging in the Diagnosis of Carcinoma of the Papilla of Vater: Usefulness of Procedures of Diagnostic Imaging Modalities

要旨　乳頭部癌の進展度診断を検討した．USで腫瘍が描出できたものはなかった．CTの腫瘍描出率は54.5％であったが，US，CTとも全例で膵・胆管拡張などの副次所見を認めた．血管造影では腫瘍径が10mm以下の2例に異常がなく，llmm以上では80％以上に異常がみられた．EUSは十二指腸浸潤の有無が全例で正診できたが，膵浸潤の正診率は77.8％であった．IDUSも十二指腸浸潤の有無は全例で正診でき，膵浸潤は有無，程度とも全例で正診できた．MRCPはERCPが不能であった症例で膵管の描出が可能であった．乳頭部癌の存在診断にはUS，CT，MRCPが，進展度診断には血管造影，EUS，IDUSが有用であった．

　Forty-two patients with carcinoma of the papilla of Vater were studied. Ultrasound (US) and computed tomography (CT) were used as screening procedures. In all patients dilatation of the pancreatic duct and/or bile duct was demonstrated, but it was difficult to depict the tumor. MR cholangiography (MRCP) clearly showed a filling defect in the papilla of Vater and proximal pancreatobiliary duct dilatation. Angiography, endoscopic ultrasound (EUS) and intraductal ultrasound (IDUS) were performed for preoperative staging. Angiography showed no abnormality in tumors smaller than 10 mm, but arterial encasement and tumor stain were demonstrated in over 80% of tumors larger than 11 mm. Angiography correctly diagnosed duodenal invasion in 77.4% and pancreatic invasion in 87.1%. Duodenal invasion was readily demonstrated by EUS and IDUS. EUS was valuable in the detection of pancreatic invasion, but minimal invasion was depicted only by IDUS. Integrated diagnosis with angiography, EUS and IDUS was highly accurate in the preoperative staging of carcinoma of the papilla of Vater.