腺腫からの癌化が示唆された膵管内乳頭腺癌の1例

Carcinoma in Intraductal Papillary Adenoma of the Pancreas, Report of a Case

要旨　膵頭部膵管一次分枝に発生した膵管内乳頭腺腫の一部に乳頭腺癌を含む症例を経験した．患者は52歳，女性．1986年5月当院人間ドック受診し，腹部超音波断層法（US）で膵頭部の腫瘤と主膵管の拡張を指摘され，当科に入院した．内視鏡的超音波断層法（EUS）および内視鏡的逆行性胆膵管造影法（ERCP）で嚢胞状に拡張した膵頭部膵管一次分枝内に充実性の腫瘤を認めた．親子方式経口的膵管内視鏡検査（PPS）で膵管一次分枝内に乳頭状に発育した有茎性の腫瘍が観察され，直視下生検で乳頭腺癌と診断された．膵頭十二指腸切除術による病理組織学的検索では，腫瘍の大部分は膵管内乳頭腺腫であったが，一部にはsevere dysplasiaが認められ，更に一部は高分化型乳頭腺癌の組織像を呈した．本例は膵管内乳頭腺腫の癌化を示唆する極めて興味ある症例である．

　A 52-year-old woman, asymptomatic, was seen because of a small tumorous lesion in the pancreatic head demonstrated by conventional ultrasonography. Endoscopic ultrasonography (EUS) showed a tumor mass in the dilated pancreatic duct. Endoscopic retrograde pancreatography (ERP) also revealed a tumor located within a cystically dilated branch duct of the head of the pancreas. Peroral pancreatoscopy (PPS) was performed to further elucidate the nature of the lesion. It was shown as a pink-reddish papillary tumor by PPS. Examination of biopsy specimen obtained under direct observation revealed papillary adenocarcinoma of the pancreas.

　Pancreatoduodenectomy was performed. Examination of the resected materials showed papillary tumor, 18×15×13 mm in size, in the first branch of the pancreatic duct. Histologically, the tumor proved to be an adenoma with severe dysplasia containing focal malignant change.