肿瘤伴随症候群指身体因为肿瘤生长引起在荷尔蒙、神经系统、血液，生化平衡等方面出现紊乱的临床症状。

通常有下列几类：

A paraneoplastic syndrome is a syndrome (a set of signs and symptoms) that is the consequence of cancer in the body but that, unlike mass effect, is not due to the local presence of cancer cells. These phenomena are mediated by humoral factors (by hormones or cytokines) excreted by tumor cells or by an immune response against the tumor.