無黄疸で発症し洗浄細胞診で診断された早期胆管癌の1例

Early Carcinoma of the Bile Duct without Jaundice Diagnosed by Cytology of Washings, Repert of a Case

要旨　71歳，男性．上腹部不快感を訴えたため腹部超音波検査を施行し，軽度の胆管拡張を認めたため経皮経肝胆管ドレナージ術を施行した．胆汁の洗浄細胞診で悪性細胞が証明されたため，下部胆管癌の診断で膵頭十二指腸切除術を施行した．組織学的に深達度，m，hinf₀，ginf₀，panc₀，d₀，vs₀，dw₀でStageIであった．早期胆管癌の定義については，種々の論議があり，報告者により様々であった．今回改訂となった胆道癌取扱い規約では，組織学的深達度が粘膜（m）内または線維筋層（fm）内にとどまるもので，リンパ節転移を問わないと規定された．近年，画像診断の進歩と共に早期胆道癌も発見される機会が多くなってきているが，胆管癌では，いまだにその早期診断は困難である．肝外胆管癌においては，黄疸を契機に発症することが多く，ほとんどが進行癌である．無黄疸症例でも不定愁訴に加え，ALP，γ-GTP，LAPなどの胆道系酵素の上昇に注意することや，腹部超音波検査，DIC，更に，ERCP，PTCによる直接造影を積極的に行うことにより診断の向上に努めるべきと考える．

　The patient was a 71-year-old man. He complained of upper abdomen discomfort. Abdominal ultrasonography revealed mild dilatation of the bile duct, and percutaneous transhepatic bile duct drainage was conducted. As cytodiagnosis of bile washings demonstrated malignant cells, the patient was diagnosed as hawing carcinoma of the lower bile duct and had to undergo pancreatoduodenectomy. This case was m in histological depth, hinf₀, ginf₀, panc₀, d₀, vs₀, dw₀ and Stage I. The definition of early carcinoma of the bile duct varies according to researchers. The recently revised"General Rules for Surgical and Pathological Studies on Cancer of the Biliary Tract"specify that it should be, in histological depth, m (mucous membrane) or fm (fibromuscular layer) and with or without lymph node metastasis. Recent progress in imaging diagnosis has increased the frequency of detection of carcinoma of the biliary tract, but its early diagnosis is still difficult. The onset of extrahepatic carcinoma of the bile duct is accompanied with jaundice but, by then, carcinoma is advanced in most cases. Even in cases without jaundice, unidentified clinical syndromes and increase of ALP, γ-GTP, LAP and other biliary tract-derived enzymes should be noted. We should try to improve diagnosis by positively conducting direct imaging like ERCP and PTC, in addition to abdominal ultrasonography and DIC.