adult T-cell leukemia（ATL）の大腸病変

Involvement of the Large Intestines in Patients with Adult T-cell Leukemia

要旨　7症例のATLの大腸病変についてX線像および内視鏡像の特徴と腫瘍細胞の浸潤様式について検討した．病変はほぼ大腸全体に広範囲にみられた．画像所見および腫瘍細胞の浸潤様式を考慮し，肉眼型をびまん浸潤型，多発びまん浸潤型および多発結節型の3つに分類した．びまん浸潤型は腫瘍細胞が腫瘤をつくらず，大腸壁をびまん性に浸潤するタイプで2例みられた．画像上はそれぞれ，びまん性の微細顆粒状隆起と顆粒状隆起を呈した．このほかにびまん浸潤型として，文献例では脳回様の粘膜肥厚を呈す症例もみられた．多発びまん浸潤型は腫瘍細胞が小さな腫瘤をつくり，びまん性に浸潤するタイプであり1例みられた．画像上はたこいぼびらん様隆起が密在してみられた．また，多発結節型は腫瘍細胞がポリープまたは結節状の腫瘤をつくり多発散在するタイプで，腫瘤の中心にびらんまたは小潰瘍を伴うことが多かった．多発結節型は4例みられ，画像上はMLP様の所見を呈した．びまん浸潤型は難治性の下痢を呈したが，他の病変では腫瘍細胞の浸潤による下痢はみられなかった．ATLは基本的には全身性悪性リンパ腫であるが，白血化しやすく，また臓器浸潤傾向が強いという性格も合わせて持っており，このことが腫瘍細胞の浸潤の様式と程度に密接に関係し，大腸病変を多彩にしていると考えられた．

　We studied involvement of the large intestine in seven patients with adult T-cell leukemia (ATL) with regard to radiographic as well as endoscopic characteristics and infiltrative forms of the tumor cells.

　The large intestine was found to be extensively involved in all the patients. We classified the cases into three types according to the radiographic and endoscopic findings as well as to the infiltrative forms of tumor cells: 1) diffusely infiltrating type, 2) multiple and diffusely infiltrating type, 3) multiple nodular type. In the diffusely infiltrating types, tumor cells diffusely infiltrate to the intestinal wall without mass formation. Radiographically and endoscopically, each of our two cases of this type showed a fine granular pattern or a granular pattern of the mucosa. A gyri-like appearance is also reported in this type. In the multiple and diffusely infiltrating type, tumor cells diffusely infiltrate with innumerable small elevated lesions. Our case of this type had an appearance resembling extensivelyspreading erosive gastritis. In the multiple nodular type, tumor cells infiltrated forming multiple polypoid lesions with central depression. Our four cases of this type had the appearance of so-called multiple lymphomatous poyposis (MLP).

　Our patients with diffusely infiltrating type tumor cells suffered from refractory diarrhea that was suspected to be caused by the infiltrated tumor cells, but such diarrhea was not seen in the patients of the other two types.

　ATL is one of the systemic multiple lymphomas that has a strong tendency to infiltrate to various organs and/or to be leukemic. It is suggested that such characteristics of ATL are closely related to the various forms and degree of infiltration of tumor cells, causing variform lesions in the large intestine.