空腸原発性NK/T細胞リンパ腫の1例

Primary Jejunal NK/T Cell Lymphoma, Report of a Case

要旨　症例は78歳，女性，貧血精査目的で近医から紹介入院となった．順行性小腸造影検査でTreitz靱帯より20cm肛側に8cm大の不整形バリウム貯留を認め内部は囊状に拡張していた．小腸内視鏡検査ではほぼ全周性の不整潰瘍であり辺縁部に上皮性腫瘍の所見を認めなかった．腹部CTで8cm大の空腸原発，非上皮性腫瘍を疑う所見を認めWood分類による動脈瘤型悪性リンパ腫と診断した．貧血が進行するために治療は小腸切除術を施行した．免疫学的検索を含めた組織学的結果では隣接回腸に直接浸潤を来したNK/T細胞性リンパ腫（CD3，CD56陽性，CD20陰性）であり術後化学療法が予定されたが全身状態が改善せず術後約4か月で死亡した．

　An asymptomatic 78-year-old woman was admitted to hospital in Dec., 2003, for investigation relating to her anemia. Laboratory data showed a high level of sIL-2 receptor (925U/ml). Small bowel radiography and push enteroscopy revealed a deep irregular ulceration 8cm in diameter but without intestinal stenosis at the upper jejunum, and suggested an aneurysmal type of intestinal malignant lymphoma, which was pathologically verified by endoscopic biopsy. Systemic CT scan showed no lymphadenopathy and no hepatic or pulmonary metastasis. The patient had initially undergone surgery for progressive anemia. During laparotomy, the tumor was located in the jejunum and had directly invaded the neighboring ileum. Immunohistochemical studies of the resected tumor showed that tumor cells were positive for CD3 and CD56, but negative for CD20 and CD79α. On the basis of these findings, this case was diagnosed as NK/T cell lymphoma of the small intestine. The patient died about four months after surgery because of this progressive disease, consistent with the poor prognosis of NK/T cell lymphoma.