術前診断できた多発微小Ⅱb～Ⅱc型早期胃癌の1例

A Case of Multiple Minute Ⅱb～Ⅱc Early Gastric Cancer Diagnosed before Operation

　いま10mm以上の早期癌ならルーチンに診断でき，5～10mmの小さなものでも注意深いX線検査でひろい上げ確診できるようになった．だが，より小さな5mm以下の微小癌，それもⅡbのような粘膜の凹凸の差のないものでは，診断が不能であると思われていた．しかし，最近，生検がルーチン化するにしたがって，少しずつではあるが，このような微小Ⅱb病変が術前診断されるようになっている．われわれも，術前に2ヵ所の微小Ⅱb，Ⅱc病変と診断し，切除標本の組織学的検索で12ヵ所に切片上，最小0.2mm，最大3mmまでのⅡb～Ⅱc型微小癌巣が発見された症例を経験した．この症例でX線，内視鏡診断の限界について検討したので報告する．

　症　例

　患　者：51歳　家婦

　主　訴：胃部不快感，筋肉痛

　家族歴：父親，59歳時，肺癌で死亡

　既往歴：10歳，胃潰瘍，19歳，結核性腹膜炎，20歳，胸膜炎，29歳，リウマチ熱，39歳，巨大結腸切除術

　現病歴：10歳時，吐血し某医で胃潰瘍と診断されている．その後も時々上腹部痛があり，胃潰瘍と診断され治療を受けていた．1974年2月胃部不快感があり，某医で胃X線・内視鏡倹査を受け，胃潰瘍と診断され入院加療している．1974年9月全身の関節痛が強くなり，リウマチ熱と診断され，以来，今日までプレドニソロン5～10mgを連用してきた．1976年5月，同様の主訴と筋力低下を自覚し，精査を求めて本院膠原病内科を受診した．臨床症状より多発性筋炎または皮膚筋炎を疑われ，胃潰瘍の既往もあり，胃の悪性腫瘍を否定する必要があった．胃X線・内視鏡的に精査し，多発微小胃癌と診断した．

　In a case of multiple minute gastric cancer which was diagnosed preoperatively, with lesions located at two sites, the postoperative histologic examination revealed lesions of Ⅱb～Ⅱc types, not more than 5 mm in diameter, at 12 sites. This was the case of a 51-year-old housewife with a past history of gastric ulcer over 40 years, recently complicated by the symptoms and signs of polymyositis or dermatomyositis.

　In the first X-ray examination, this case was diagnosed as multiple ulcer scars and erosive gastritis, but in the subsequent endoscopic examination, a very small reddened area was found at the gastric angle where an ulcer scar had been roentgenographically diagnosed, and biopsy showed a signet ring cell carcinoma. The area was thereafter endoscopically found only discolored, and diagnosed as minute Ⅱb carcinoma. Another new small reddened area was found antral to the previous one, where biopsy again showed a signet-ring cell carcinoma. The mucosa between the two areas being normal, they were independent from each other. The X-ray examination in detail of these two areas confirmed the occurrence of the two lesions at different sites but we failed to qualitatively diagnose them. The macroscopic examination of the resected stomach specimen revealed that the first lesion looked like an ulcer scar, while the second was a small erosion. The roentgenogram after the resection showed what are called malignant findings in a part of the margin of the small erosion.

　The histologic examinations of the sections of the resected specimen at 5 mm intervals disclosed that the two lesions were Ⅱb-like Ⅱc lesions, 1 to 2.5 mm in diameter, on the sections. Furthermore, lesions of Ⅱb～Ⅱc types 0.2～3 mm in diameter, were found at a total of 10 sites where no abnormalities could have been predicted preoperatively. All the lesions were signet-ring cell carcinomas confined to the mucosa, and 11 of them occurred in the intermediate zone. In 11 lesions, cancer cells were found only near the neck of the gland; and the lesions consisted of typical Ⅱb lesions at nine, and Ⅱb-like Ⅱc lesions at three sites. Atrophy of the gastric glands and inflammatory cell infiltrations were striking in the mucosa around all the cancer lesions, but intestinal metaplasia was absent. Thus, this was a very interesting case for the study of histogenesis of carcinoma.