転移性大腸腫瘍の画像診断・形態学的特徴

Clinical and Endoscopic Features of Metastatic Colorectal Tumors

要旨●当院を含めた3施設で2010年1月〜2021年12月の間に転移性大腸腫瘍96例113病変の臨床的特徴と内視鏡所見を検討した．原発臓器は胃と卵巣が各21例と最多で，次いで膵臓12例，子宮8例の順に多かった．転移経路は腹膜播種転移が45例と最多で，直接浸潤が35例，血行性・リンパ行性転移が16例で，86例が単発転移であった．胃癌や膵癌では腹膜播種転移，卵巣癌，子宮癌，膀胱癌や前立腺癌では直接浸潤，肺癌では血行性・リンパ行性転移が多かった．直接浸潤や腹膜播種転移では管腔狭小化を来す例が多く，直接浸潤ではびらんや潰瘍を伴うなだらかな粘膜下腫瘍（SMT）様隆起，腹膜播種転移では敷石様粘膜，血行性・リンパ行性転移ではSMT様の立ち上がりを呈する潰瘍やびらん，上皮性腫瘍様の形態が特徴的であった．

　Ninety-six patients with a total of 113 metastatic colorectal tumors between January 2010 and December 2021 at three institutions including our hospital were evaluated clinically and endoscopically. Gastric cancer was the primary form of cancer in 21 cases, ovarian cancer in 21, pancreatic cancer in 12, and uterine cancer in 8. In 45 cases, tumor invasion was observed via peritoneal dissemination, 35 via direct invasion, and 16 via hematogenous/lymphatic metastasis. The majority of metastases were single lesions（86 cases）. Peritoneal dissemination was common in gastric and pancreatic cancer, as was direct invasion in ovarian, uterine, bladder, and prostatic cancer, and hematogenous/lymphatic metastasis in lung cancer. Stenosis or a gently sloping submucosal tumor-like lesion with erosion or ulceration is common in directly invaded tumors. Tumors that spread through the peritoneum had cobblestone-like mucosa. Tumors that spread through hematogenous/lymphatic channels showed erosion or ulceration with submucosal tumor-like elevation, such as a bull's eye lesion, or epithelial tumor-like elevation, such as a type 0-IIc lesion.