I: Paraneoplastic Syndromes

Paraneoplastic syndromes are conditions that occur in association with malignancy but not due to the local presence of malignant cells and not due to endogenous hormone production.

They are typically due to ectopic production of hormones by cancer cells (e.g. SIADH from small cell carcinoma, PTHrP from squamous cell carcinoma) or autoimmune reactions, although the exact mechanism remains elusive in some cases.

The common paraneoplastic syndromes are listed below. Conditions due to endogenous hormone production (eg. hypoglycaemia from insulinoma) are typically not included as paraneoplastic phenomenon as they are due to the normal function of the malignant cells.

Metabolic

Cancer Cachexia

Hypercalcaemia

Cushing's Syndrome

Syndrome of Inappropriate ADH

Carcinoid Syndrome

Haematological

Anaemia

Venous Thrombosis

Neuromuscular

Myasthenia Gravis

Lambert Eaton Syndrome

Most commonly seen in association with small cell lung cancer and much rarer than myasthenia gravis. It is due to autoantibodies directed against voltage gated calcium ion channels, which leads to impaired release of acetyl choline. Treatment of the underlying malignancy, symptomatic treatment with 3,4-DAP and immunotherapy are all treatment options.

Dermatomyositis

Paraneoplastic Encephalitis

Other

Clubbing

Fever


Links