特殊型胃癌の臨床病理学的特徴

Clinicopathological Characteristics of Special-type Gastric Carcinoma

要旨●胃癌の組織型は，胃癌取扱い規約において一般型と特殊型に分類されている．特殊型胃癌はいずれもまれなものであるが，病理組織学的に腫瘍細胞の充実性増殖を示すものが多く，低分化腺癌充実型，悪性リンパ腫，肉腫などとの鑑別が必要となる．また，臨床的にも予後が著明に不良なものや一般型胃癌よりも予後良好なものがあり，特殊型であっても組織型の特定は重要である．本稿では，特殊型胃癌の各組織型について発生機序を含めた臨床病理学的特徴を網羅的に示した．

　In the Japanese classification of gastric carcinoma, gastric cancer is histologically classified into the general and special types. The special types of gastric cancer are relatively rare. Histologically, several special-type gastric cancer show solid proliferation of tumor cells ; therefore, it is necessary to distinguish them from poorly differentiated adenocarcinoma solid types, malignant lymphomas, and sarcomas. Clinically, special-type gastric cancer can either have a significantly worse prognosis or a better prognosis than general-type gastric cancers. Hence, the histological identification of the special-type gastric cancers is important. This paper comprehensively demonstrates the clinicopathological features, including the pathogenesis, of each special-type gastric cancer.