牛眼像の多発を示した全身性悪性リンパ腫胃転移の1例

Metastatic Malignant Lymphoma of the Stomach Presenting with Multiple Bull's-Eye Lesions, Report of a Case

要旨　78歳，男性．主訴は右上腹部痛．胃X線検査で胃のほぼ全域に中心陥凹を有する大小の隆起が多発し，あるものは牛眼像を呈した．胃内視鏡検査でも同様の所見で，中心陥凹に凝血の付着をみるものもあり，生検で悪性リンパ腫が疑われた．腹部CTは傍大動脈リンパ節の著明な腫大を示した．経過中，吐血のため胃を全摘．切除胃肉眼標本では胃の全域に大小の隆起が不規則に多発し，多くは中心陥凹を伴っていた．組織学的に，隆起は粘膜最表層を残して粘膜層から粘膜下層にdiffuseに増殖した腫瘍細胞から成り，後腹膜リンパ節原発と推測されるdiffuse large cell type悪性リンパ腫の胃転移と診断した．転移性胃腫瘍の診断は，本例のように牛眼像の多発を伴った場合には容易である．

　A 78-year-old man was admitted to our hospital complaining of right upper abdominal pain on June 23, 1986. A chest radiograph was normal. Superficial lymphnodes were not palpable on physical examination. Double contrast study of the stomach disclosed multiple filling defects of varying size with central ulceration, consistent with bull's-eye sign (Figs. 1-4). These findings were confirmed on endoscopic examination (Figs. 5 and 6). Biopsy specimen indicated abnormal cells highly suggestive of malignant lymphoma. CT examination revealed marked swelling of paraaortic lymphnodes (Fig. 7). Intestinal involvement was denied clinically. Ten days after admission, emergency total gastrectomy was performed because of sudden onset of hematemesis.

　The resected stomach showed multiple polypoid lesions of varying size, with or without central ulceration throughout the entire mucosa (Fig. 8). Histological examination disclosed metastatic malignant lymphoma (non-Hodgkin, diffuse large cell type), possibly originated from paraaortic lymphnodes, and these lymphoma cells were present in the mucosal and submucosal layers of protruded lesions (Figs. 9-12). In addition, minute metastatic lesions were seen macroscopically in the flat areas of the mucosa of the stomach and duodenum. The patient expired on the following day after operation. Autopsy was not performed.

　Diagnosing metastasis of malignant neoplasm to the stomach is often difficult. It is, however, rather easy when multiple bull's-eye lesions which are characteristic to gastrointestinal metastatic lesions are shown as illustrated in our case.