結節性動脈周囲炎における腸潰瘍の病理学的特徴

Pathological Study on Characteristic of Intestinal Ulcer of Periarteritis Nodosa

要旨　外科切除あるいは剖検された7例の結節性動脈周囲炎（PN）の腸を病理学的に検索した結果，PNにおける小腸潰瘍の肉眼的特徴は以下のごとくであった．①多発性で，潰瘍間に軽度浮腫状またはほぼ正常の粘膜を残す，②腸間膜付着対側に好発する，③形は主に不整形，大きなものでは腸間膜側に拡がる傾向があり，亜輪状，輪状となるが，概して腸間膜付着対側で幅が広い，④腸管長軸方向の長さの長いものは少なくほぼ3cm以下である，⑤深さは浅い（Ul-Ⅰ～Ⅱ）．以上の結果に加え，潰瘍以外の腸病変として動脈瘤からなる粘膜下腫瘍様小結節と血腫を指摘した．これらを基に，組織学的所見および文献的知見を加味し，また，PNにおける腸潰瘍の肉眼的特徴，成因，鑑別診断について考察を加えた．

　Bowels of 7 cases of periarteritis nodosa accompanied with vasculitis were studied clinicopathologically. In two cases, the bowels were surgically resected. In five cases they were necropsied. All of the seven cases had some lesions including ulcers, erosions, necrosis, hematomas, aneurysms etc in their bowel walls. Six cases revealed ulcers in the small bowel showing the following characteristics. These ulcers (1) were multiple and separated by mildly edematous or almost normal mucosa, (2) had a tendency to be located at the antimesenteric border, (3) were predominantly irregular in shape and frequently extended toward the mesenteric border to form subannular or annular ulcers, when they were wider at the antimesenteric border than at the mesenteric border, (4) were less than 3 cm in width along the long axis of the bowel, and (5) were shallow.

　Histopathologically these ulcers showed essentially the same features as in ischemic enterocolitis. Necrotizing arteritis in the acute inflammatory or granulationtissue stage was encountered in the bowel walls or in the mesenteric fat near the ulcers except for one case with arteritis in a healed stage, who had been treated with steroids for a month. In three autopsy cases more than two dome-shaped small submucosal nodules made up of aneurysms were scattered. According to the results obtained, macroscopic characteristics, causative factors and differential diagnosis of ulcer in the bowel of patients with periarteritis nodosa were briefly discussed, and the ulcers of earlier Japanese reported cases were reviewed.