colitic cancer/dysplasiaの病理組織学的特徴

Histopathologic Characteristics of Ulcerative Colitis-associated Colorectal Epithelial Neoplasia

要旨　潰瘍性大腸炎（以下UC）合併sm以深浸潤癌7症例を用いて，そのsm以深浸潤部と随伴粘膜内腫瘍部の組織所見を検討した．随伴粘膜内腫瘍は腺癌と腺腫とに診断された．粘膜内癌の組織型は高分化～低分化・印環細胞癌まで多彩であった．高分化腺癌は①通常型，②表層分化型，③BC型（basal cell proliferation），④PC型（pancellular dysplasia）の4型に分類され，低異型度癌が高頻度であった．sm以深浸潤部癌は低分化腺癌・印環細胞癌・粘液癌と高分化低異型度癌の頻度が通常大腸癌に比べ高く，UCに発生した高分化腺癌は低異型度であっても粘膜下層浸潤能が高い可能性が推定された．粘膜下層以深に浸潤しやすい癌に特異的な組織所見は得られなかったが，BC型粘膜内癌は他の型とは異なる発育様式を示す浸潤癌に生長する可能性が示唆された．

　Intramucosal neoplasias associated with ulcerative colitis (UC) were diagnosed either as adenocarcinoma or adenoma. Adenocarcinoma were classified into the following four histologic patterns ; ① common type, ② superficially differentiated type, ③ BC type (basal cell proliferation) or ④ PC type (pancellular dysplasia) . Carcinoma with low-grade atypia were frequent. UC-associated invasive colorectal carcinomas (CRC) included various histologic types. Poorly differentiated type, signet ring cell carcinoma, mucinous carcinoma, and well differentiated carcinoma with low-grade atypia were relatively frequent compared to those seen in sporadic CRC. It was suggested that UC-associaed CRCs with low-grade atypia have a high invasive potential unlike those in sporadic CRC. Although neither of the four histologic pattens indicated higher invasive potential, it is suggested that BC type might develop into CRC with a growth pattern different to those would develop from the other types.