Paraneoplastic syndromes

Disease class: Neoplasms

Types

• Nervous system paraneoplastic syndromes  
• Paraneoplastic endocrine syndromes

Both malignant neoplasms (cancers) and benign neoplasms, can cause dysfunction through local effects. However, they can also cause widespread diseases by secreting signalling molecules and promoting autoantibodies. These diseases are known as paraneoplastic syndromes.

Many of these diseases are highly destructive, and they are associated with significant morbidity and mortality.

 

General mechanisms of paraneoplastic syndromes

Cancer cells are often genetically unstable and colonies of clones will arise which have loss-of-function and gain-of-function mutations. This means some genes become active, which should be inactive. Some genes become inactive, which should be active. This leads to dysregulation of the synthetic and secretory functions of cells. The mutant cells may synthesise and secrete new products.

When cells in the body become neoplastic, they expand to excessively large populations. If the cell type is a secretory cell, e.g. a neuroendocrine cell, the total quantity of this secretion may become excessive. This result in increased endocrine or paracrine signalling.

Additionally, dysplasia can stimulate the immune system and trigger clonal selection against new antigens. This can trigger the development of autoantibodies, causing autoimmune diseases.

Mucocutaneous

Haematological

Other