スキルス胃癌の病理診断

Pathological Diagnosis of Scirrhous Gastric Cancer

要旨●スキルス胃癌の病理診断について，①その歴史的な定義，②肉眼的・病理組織学的特徴，③同様のあるいは類似の病変を示す4型胃癌・linitis plastica型胃癌などの術語との異同，④実臨床上の捉えられ方，について述べた．病理組織学的には，発生部位，肉眼型，組織型，拡がりなどによらず，線維性結合組織の高度な増生を伴うものがスキルス胃癌に相当する．病理学的にスキルス胃癌と診断される病変には，linitis plastica型，幽門狭窄型，3型スキルス胃癌，0-IIc型スキルス胃癌などがある．一方，臨床的にスキルス胃癌という場合，多くは，胃底腺粘膜領域に原発巣があり，急速に進行し，広範な進展を示して胃壁の硬化と収縮を伴うlinitis plastica型胃癌か，幽門前庭部に原発巣がある幽門狭窄型のいずれかを指すことが多い．また，4型胃癌という場合は，linitis plastica型胃癌の他に，胃壁の硬化を伴わず，低分化腺癌細胞が個細胞性・小胞巣性に遊走するがごとく拡がるものが含まれる．

　This article introduced the pathological diagnosis of scirrhous-type gastric cancer, including its historical issues, definition, macroscopic, and histological characteristics, and its relationship with type 4 and linitis plastica-type cancer. Histologically, gastric cancer with prominent fibrotic stroma is regarded as scirrhous-type cancer irrespective of the tumor location, macroscopic type, histological type, and distribution. From a pathological standpoint, scirrhous-type cancer is classified as either linitis plastica type, pyloric stenosis type, type 3 scirrhous cancer, or morphological type 0-IIc scirrhous cancer. However, from a clinical point of view, only linitis plastica and pyloric stenosis types are regarded as scirrhous-type cancer. Notably, type 4 cancer includes nonscirrhous cancer with the migration of isolated or small nested cancer cells in the stroma.