胃底腺型腺癌の予後と治療方針

Prognosis and Treatment Strategy for Gastric Adenocarcinoma of the Fundic Gland Type

要旨●胃底腺型腺癌は，胃底腺細胞への分化を伴う低悪性度の腫瘍である．多くは小径で粘膜内または粘膜下層に限局し，脈管侵襲やリンパ節転移は極めてまれであることから，内視鏡切除術のよい適応である．術後の予後は良好で，局所再発はほとんどないが，一部の症例で同時性または異時性に胃底腺型腺癌の発生がみられる点に注意が必要である．一方，胃底腺粘膜型腺癌は腺窩上皮への分化を伴い，より悪性度が高いとされるが，長期予後の解明は今後の課題である．

　Gastric adenocarcinoma of the fundic gland type is a low-grade malignant tumor characterized by differentiation into fundic gland cells. In most cases the tumors are small and are confined to the mucosa or the submucosa. Vascular invasion and lymph node metastasis is extremely rare, making endoscopic resection an excellent treatment option for these tumors. It is associated with a favorable postoperative prognosis and a minimal risk of local recurrence. However, careful follow-up is recommended since synchronous or metachronous development of gastric adenocarcinoma of the fundic gland type has been reported in some cases. In contrast, gastric adenocarcinoma of the fundic gland mucosa type is considered to have a higher degree of malignancy as it exhibits differentiation toward foveolar epithelium. However, further investigation is required to clarify the long-term prognosis.