開放性潰瘍合併未分化型胃癌の1例―特に深達度診断に関する組織構築の検討

Undifferentiated-Type Gastric Carcinoma with Ulceration, Special Reference to Invasive Depth by Histological Study, Report of a Case

要旨　患者は50歳，女性．開放性潰瘍を伴う未分化型胃癌（深達度mp，20×15mm）で，術前深達度診断上，病巣内潰瘍および小規模な周堤形成の組織学的な成り立ちの推定が問題となった症例である．潰瘍合併胃癌では，潰瘍の修飾によって癌の深部浸潤に類似した所見が現われる場合があり，術前の深達度診断は容易でないとされている．画像所見と組織所見とを対比分析した結果，これらの組織学的な成り立ちは粘膜下層主体に線維形成反応を伴う癌によるものであった．更にsm浸潤部の癌量（密度）の分布が不均一で，病巣中心部ほど癌が密に存在し病巣辺縁部ほど疎であった．このため，画像上認められた胃壁の伸展不良・硬化所見が消化性潰瘍による炎症性変化よりも強く，癌量の多い進行癌に比べて弱かったものと推定した．深達度診断精度の向上には，X線・内視鏡の動的観察によって胃壁の肥厚および伸展不良・硬化所見の程度判定を行い，総合的な病変構築を推定することが重要と思われた．

　It is generally considered that preoperative diagnosis of invasive depth is not easy in gastric carcinoma particulaly when it is associated with ulceration.

　Our case is a Ⅲ ＋ Ⅱc type mp gastric carcinoma sized 20 × 15 mm in a 50-year-old housewife.

　Concerning this lesion, comparative studies of endoscopic and radiographic findings with histological examination revealed that the ulceration in the lesion and surrouding elevation consisted, histologically, of submucosal adenocarcinoma with reactive fibrosis.

　Histological sm-invasion of this carcinoma was more dense at the lesional center than at the periphery. This can produce a greater sclerotic appearance on endoscopic and radiographic imaging. Usually, sclerotic appearance of the gastric wall is more enhanced in cases of invasive carcinoma than the inflammatory change brought about by peptic ulceration.

　The lesion in this case showed an intermediate degree of sclerotic appearance between the inflammation and the massive carcinoma. This finding was thought to be due to the histological density of the carcinoma.

　In diagnosing such gastric carcinoma with ulceration, it is essential to evaluate the thickness and sclerotic appearance of the gastric wall using air-inflation or deflation in the endoscopic and radiographic examinations.