十二指腸非乳頭部隆起性病変─十二指腸リンパ腫の診断

Diagnosis of Duodenal Lymphoma

要旨●十二指腸リンパ腫は組織型によって特徴的な内視鏡像を呈する例も多い．過半数を占める濾胞性リンパ腫は，十二指腸下行脚の白色調のびまん性小顆粒状所見が特徴的であり，小腸病変も高率に併存するため，小腸内視鏡検査も施行すべきである．びまん性大細胞型B細胞性リンパ腫は潰瘍型が多いが，隆起型や混在型もみられる．MALTリンパ腫はMLP（multiple lymphomatous polyposis）型，隆起型が多く，Helicobacter pylori感染陽性例では除菌により寛解に至る例も多い．マントル細胞リンパ腫は診断時既に進行期であることが多く，また，消化管にも広範囲に分布していることが多い．十二指腸ではMLP型を呈しているものが多い．

　Duodenal lymphoma often exhibits characteristic endoscopic findings depending on the histological types. Follicular cell lymphoma, which accounts for most cases of duodenal lymphoma, is distinctive with the whitish diffuse small granular appearance in the descending part of the duodenum. In addition, a small intestinal endoscopic examination should be performed because of a high possibility of the existence of small intestinal lesions. To date, several cases of ulcerative form in diffuse large B-cell lymphoma in the duodenum have been reported, and both protruding- and mixed-type lymphoma have been observed. Moreover, several cases of MLP（multiple lymphomatous polyposis）-type and protruding-type mucosa-associated lymphoid tissue lymphoma have been reported. In Helicobacter pylori-positive cases, several cases have been known to result in remission only through eradication therapy. Often, mantle cell lymphoma is diagnosed at an advanced stage, in which the lymphoma has already broadly spread to the digestive tract, mostly accounting for MLP-type in the duodenum.