背景粘膜からみた小さな未分化型胃癌の特徴

Characteristics of Small Undifferentiated Gastric Cancer with Respect to Background Mucosa

要旨　(1)長径20mm以下の病変を対象として，未分化型早期胃癌74例82病変を分化型早期胃癌143例166病変および進行癌25例25病変と対比させ，その臨床病理学的特徴を検討した．(2)分化型早期癌に比べて未分化型早期癌は女性に圧倒的に多く，平均年齢も低いが，Ul合併率およびsm率ははるかに高率であった．(3)未分化型早期癌はその背景粘膜の違いによって性状が異なる．F領域のものは，進行癌との性別，平均年齢，分布などの対比から，linitis plastica型癌へ発育進展する可能性が高いことが示唆され，Ⅰ領域のものは，Ul合併率，sm率ともに最も高く，臨床的に早期発見しやすい形態を呈するものが多い．一方，P領域のものは他の領域の未分化型癌と違って，臨床病理学的に分化型癌に類似した性質を帯びている．

　Clinicopathological study was undertaken by comparing small undifferentiated gastric cancer (82 lesions in 74 cases) with differentiated early type (166 lesions in 143 cases) and advanced type (25 lesions in 25 cases) cancers. Longer diameter was less than 20 mm in all lesions.

　Undifferentiated early cancer was distinguished from differentiated type in that the former occurred far more frequently in females and younger patients. Complication rate of Ul and frequency of sm type were much higher in an undifferentiated early cancer group than in a differentiated early cancer group. Nature of undifferentiated early cancer differed according to its background mucosa. Comparison of it with advanced gastric cancer regarding sex ratio, average age, and distribusion suggested that the lesions of F area transform with high probability to linitis plastica type. It was also suggested that the lesions of I area are likely to be detected early because of its structural changes, i.e., higher Ul complication rate and frequency of sm type. Contrary to undifferentiated cancers of other areas, the lesions of P area tend to resemble differentiated cancer clinicopathologically.