Paraneoplastic phenomenon

From Wikipedia, the free encyclopedia

**Paraneoplastic phenomenon**
*Classification & external resources*
DiseasesDB	2064
eMedicine	med/1747

A paraneoplastic phenomenon is a disease or symptom that is the consequence of the presence of cancer in the body, but 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. Sometimes the symptoms of paraneoplastic syndromes show even before the diagnosis of a malignancy.

Paraneoplastic syndromes can be divided into 4 main categories: mucocutane paraneoplastic syndromes, neurological paraneoplastic syndromes, haematological paraneoplastic syndromes and endocrine metabolic syndromes.

1 Examples
2 Neurological
3 Organisations
4 External links

[edit] Examples

Examples of paraneoplastic phenomena:

Lambert-Eaton myasthenic syndrome (LEMS) in small-cell lung cancer
Hypercalcemia in breast cancer and lung cancer due to the production of PTHrP (Parathyroid hormone-related protein)
Paraneoplastic cerebellar degeneration associated with lung, ovarian, breast, lymphatic, and other cancers
Ectopic ACTH secretion associated with small-cell lung cancer, carcinoid tumour, thymoma and other cancers
Granulocytosis (increased granulocytes) due to the production of G-CSF
Dermatomyositis (25-50% of adult patients have an underlying malignancy) and polymyositis
Stiff-Person Syndrome (SPS)
Encephalomyelitis (inflammation of the brain and spinal cord)
Myasthenia gravis
Limbic and/or Brainstem Encephalitis
Neuromyotonia
Opsoclonus (involving eye movement)
Sensory neuropathy
SIADH associated w/ lung and CNS malignancies
Membranous glomerulonephritis
Leser-Trélat sign, a sudden onset of many pigmented skin lesions

[edit] Neurological

A particularly devastating form of paraneoplastic syndromes is a group of disorders classified as paraneoplastic neurological disorders (PNDs). These paraneoplastic disorders affect the brain and central nervous system and they are degenerative. Symptoms of paraneoplastic neurological disorders include ataxia (difficulty with walking and balance), dizziness, nystagmus (rapid uncontrolled eye movements), difficulty swallowing, loss of muscle tone, loss of fine motor coordination, slurred speech, memory loss, vision problems, sleep disturbances, dementia, seizures, sensory loss in the limbs.

The most common cancers associated with paraneoplastic neurological disorders are breast, ovarian and lung cancer, but many other cancers have been linked to PNDs as well.

Treatment options include:

Therapies to eliminate the underlying cancer such as chemotherapy, radiation and surgery, and
Therapies to reduce or slow neurological degeneration. Rapid diagnosis and treatment is critical for the patient to have the best chance of recovery. Since these disorders are relatively rare, few doctors have seen or treated PNDs. Therefore, it is important that PND patients consult with a specialist with experience in diagnosing and treating paraneoplastic neurological disorders.

[edit] Organisations

The International Paraneoplastic Association (IPA) is an organization dedicated to providing support and information to those affected by paraneoplastic neurological disorders.