特異な転移様式を呈した直腸カルチノイドとS状結腸癌の併存例

Rectal Carcinoid Associated with Sigmoid Colon Carcinoma and Liver Metastasis, Report of a Case

要旨　患者は61歳男性，階段昇降時の息切れを主訴に受診．注腸造影，大腸内視鏡検査で直腸に広基性ポリープおよびS状結腸に全周性の腫瘍を認めた．生検の結果，直腸病変はカルチノイド，S状結腸病変は腺癌であり低位前方切除術が施行されたが，直腸カルチノイドは同時性に肝転移を来しており喫状切除が行われた．更に，術後1年目にS状結腸癌の肺転移および直腸カルチノイドの再度の肝転移が発見され切除を受けた．直腸カルチノイドの報告例は近年急増しているが，他の悪性腫瘍を合併することや転移を来すことがまれならず見られるので厳重な経過観察が必要である．

　A 61-year-old man was admitted to the hospital because of shortness of breath on exertion. Blood hemoglobin concentration was 8.4 g/dl and stool was positive for occult blood. X-ray and endoscopic examination revealed a broad based polyp, 15 mm in size, of the rectum and a localized, ulcerating mass in the sigmoid colon.

　CT scan revealed two metastatic lesions in the right lobe of the liver. Low anterior resection of the rectum and wedge resection of the liver were performed. The histology of the resected specimen revealed rectal carcinoid with synchronous metastasis to the liver, and advanced sigmoid adenocarcinoma. One year later lung metastases from the sigmoid carcinoma and hepatic metastasis from the rectal carcinoid were detected and resected.

　This is a rare example of coexisting carcinoid and carcinoma of the large intestine associated with liver and lung metastasis respectively.