微小胃粘膜下腫瘍として発見しえた胃悪性リンパ腫の1例

Minute Gastric Malignant Lymphoma, Report of a Case

要旨　胃消化性潰瘍の経過観察中に発見しえた微小胃悪性リンパ腫を経験した，患者は78歳男性．74歳時より消化性潰瘍で治療を受けている．今回胃X線検査で前庭部の小隆起性病変を指摘される．胃内視鏡検査では前庭部前壁の周囲粘膜よりなだらかな移行を示す粘膜下腫蕩を思わす隆起性病変で，中心に三角形の白苔を伴う陥凹を認めた．生検により悪性リンパ腫が疑われ，1988年7月26日手術を施行した．肉眼的にはbridging foldを伴う径0.6cm大の粘膜下腫瘍で中心に陥凹を伴っていた．組織学的にはsmまで浸潤を示す大細胞型B cellリンパ腫であった．本症例は粘膜下腫瘍様の形態を示す微小胃悪性リンパ腫で，胃リンパ腫の初期像を示しているものと考えられる．

　A 78-year-old man was pointed out to have a small elevated lesion at a follow-up evaluation of gastric ulcer. Further roentgenographic and endoscopic examinations revealed a small elevated lesion resembling submucosal tumor with star-shaped erosion and depression at the center of the lesion in the anterior wall of the antrum. The surface of the lesion consisted of area gastricae as seen in the normal surrounding mucosa. This lesion was diagnosed as malignant lymphoma by biopsy. Subtotal gastrectomy was performed on July 26, 1988.

　In the resected specimen there was a small elevated lesion, measuring 0.6×0.6 cm in size，with star-shaped depression at the center in the anterior wall of the antrum. Lymphoma cells, however, have invaded in the submucosal layer.

　Histologically the tumor consisted of large cell lymphoma without nodal involvement. Immunohistological study showed that these large lymphoma cells had reactivity to B-cell antibody (MX-B).