类癌是发生于肠嗜铬细胞的实体瘤,较常见,占尸检病例的1%。而类癌综合征则罕见。根据估计,每10年出现2/25万新病例。原发肿瘤通常为小而圆,切面黄色,组织学呈带状、索状和腺泡状规则排列的多边形细胞的肿瘤。兰尾最常见,其次为小肠、结肠、胃和肺(主要在主支气管)。消化道肿瘤常位于粘膜下,向外而不向腔内扩展。任何器官均可多发,所有位置均潜在恶性,但比率不同,兰尾类癌转移极少而结肠类癌常见。不同位置的肿瘤合成和释放引起类癌综合征的各种物质的能力不同,后肠器官无此功能。如这些物质仅释入门脉循环,因可被肝清 Carcinoid tumors are solid tumors that occur in the intestinal chromaffin cells and are more common, accounting for 1% of autopsy cases. Carcinoid syndrome is rare. According to estimates, 2/25 million new cases occur every 10 years. The primary tumors are usually small, round, yellow-faced, histologically banded, cord-like, and acinar-shaped tumors of polygonal cells regularly arranged. Blue tail is the most common, followed by the small intestine, colon, stomach and lungs (mainly in the main bronchus). Gastrointestinal tumors are often located submucosally and extend outwards but not into the lumen. Any organ can be multiple, all positions are potentially malignant, but the ratio is different, the transfer of orchidoid carcinoid is very rare and common colon cancer. Tumor synthesis and release at different locations have different abilities to cause various substances of carcinoid syndrome, and the hindgut organ has no such function. For example, these substances can only be released into the circulation and they can be cleared by the liver.