十二指腸乳頭部腫瘍の鑑別診断

Differential Diagnosis of Tumor of the Papilla of Vater

要旨　十二指腸乳頭部の解剖学的，生理学的特質からみて乳頭部病変では共通した多彩な病態を呈する．乳頭部腫瘍の鑑別診断では，乳頭部炎や乳頭部嵌頓結石などの非腫瘍性病変と画像などを中心として臨床的に鑑別を要する場合と，腫瘍自身の性質について組織学的に鑑別を要する場合とが考えられる．前者では鑑別は多くは困難ではないが，後者では特に乳頭部癌との鑑別が最も重要である．腺腫と腺癌との鑑別や異型性の判定に難渋する例も少なくなく，発癌母地との関係もあって病理組織学的に議論も多い．内視鏡的生検法の限界もあり，また，Group Ⅲの取り扱い方も不明確で，疑わしきは乳頭部切除にとどまらず，一期的に膵頭十二指腸切除術を行い，全割標本の検索に委ねるべきである．

　From the anatomical and physiological point of view, there can exist a variety of lesions in the papilla of Vater. Regarding tumors of this region, we encounter two kinds of differential diagnosis. One is to clinically differentiate tumor of the papilla from non-tumor lesions like papillitis and the other is to pathologically differentiate among tumors. The former type of differentiation is not much difficult, but pathologically, we often face difficulty in differentiating adenoma from adenocarcinoma or dividing atypical cells. There is no consensus regarding the origin of cancer cells of the papilla. Moreover, endoscopic biopsy is not always perfect and there is no consensus on how to treat “Group 3” lesion. Thus, in cases of suspected malignancy of this region, it seems necessary to perform pancreatico-duodenectomy from the beginning to make a definitive pathological diagnosis, rather than to resect only the papilla of Vater.