知っておきたい十二指腸病変の病理─腺腫，癌以外の非乳頭部病変と乳頭部腫瘍

Pathological Diagnosis of Duodenal Lesions:Non-ampullary Lesions without Adenoma or Carcinoma but with Ampullary Neoplasms

要旨●腺腫，癌以外の非乳頭部十二指腸病変と乳頭部病変（乳頭部癌）について病理組織像を解説した．非乳頭部十二指腸病変のうち限局性病変（主に隆起性病変）は，内視鏡的に非腫瘍である異所性胃粘膜，Brunner腺過形成，過誤腫などの病変と腫瘍との鑑別が困難なことがある．びまん性病変は非腫瘍が多く，全身性疾患に伴う病変も観察される．病理組織学的には各疾患の診断の定義，悪性度の評価方法は整理されつつあり，病理組織像の理解は重要である．一方，乳頭部病変は内視鏡的切除も試みられるようになってきた．特に乳頭部癌は臨床的取り扱いが重要であるがいまだ不明な点も多く，臨床病理学的および分子生物学的な解明が期待される．

　Here we present a pathological diagnosis of non-ampullary duodenal lesions without adenoma or carcinoma, and ampullary neoplasms. Among elevated duodenal lesions, it is difficult to endoscopically distinguish between neoplastic lesions and non-neoplastic lesions, such as those associated with heterotopic gastric mucosa, Brunner's gland hyperplasia, and hamartoma. Diffuse duodenal lesions are often non-neoplastic and are components of systemic disease. Pathological entities and diagnostic clues related to duodenal lesions without adenoma or carcinoma have been standardized and should be understood. On the other hand, indications for the endoscopic management of ampullary lesions have increased. Effective clinical strategies for treatment of ampullary carcinoma are particularly important.Further research is needed to generate clinicopathological and molecular biological findings to improve clinical strategies for the management of ampullary carcinoma.