Paraneoplastic Syndromes


What is a paraneoplastic syndrome?

A paraneoplastic syndrome is a set of signs and symptoms that occur in people with a cancerous tumor. They develop when a malignant tumor releases a substance (hormone/protein) which affects a certain body system or when the body’s immune system releases a substance (antibody) meant to kill the tumor but also damages healthy body cells (autoimmune response).

Depending on which part of the body these substances affect, they can damage brain and muscle functions. In many cases, if the symptoms are recognized as a paraneoplastic syndrome early, it can help the doctor find malignant (cancerous) tumors in an early stage when they are most treatable.

How many people are affected by paraneoplastic syndromes?

Paraneoplastic syndromes develop in roughly 20% of people who have cancer. They occur most often in middle-aged people with breast, lymphatic, lung, or ovarian cancer.

What are the risk factors for paraneoplastic syndromes?

Risk factors include age, a previous cancer diagnosis or a family history of certain cancers. The types of cancer most likely to cause paraneoplastic syndromes are:

  • Breast
  • Gastric (stomach)
  • Leukemia
  • Lymphoma
  • Lung, especially small cell lung cancer
  • Ovarian
  • Pancreatic
  • Renal (kidney)

Symptoms and Causes

What causes paraneoplastic syndromes?

Some cancerous tumors produce chemicals which can direct certain organs in your body to work in an abnormal way. This produces signs and symptoms which would not occur in an otherwise healthy individual. If left untreated, this can lead to permanent damage of the organ system. Furthermore, your immune system can make a substance (antibody) which helps certain cells recognize tumor cells that should be killed. Sometimes the signals get crossed and these cells attack healthy tissues instead, leading to signs and symptoms not expected in a previously healthy individual.

What are the symptoms of paraneoplastic syndromes?

Symptoms of paraneoplastic syndromes vary depending on the organ systems affected. In more than half of cases, the symptoms appear before a person receives a cancer diagnosis. These syndromes' symptoms may include fever, loss of appetite and weight, and night sweats.

Less commonly, people experience other paraneoplastic syndromes, including:

  • Endocrine syndromes, which can cause:
    • High blood pressure
    • Weakness
    • Weight gain
  • Neurologic syndromes, with symptoms such as:
    • Dizziness
    • Double vision
    • Reduced reflexes, sensation, or coordination
    • Speech difficulty
    • Weakness
  • Skin syndromes, which may produce:
    • Flushing (redness)
    • Itching
    • Benign (non-cancerous) skin growths

Diagnosis and Tests

How are paraneoplastic syndromes diagnosed?

A doctor diagnoses paraneoplastic syndromes with a physical exam and several tests.

Your doctor will ask about your medical history. Because paraneoplastic syndromes affect the nervous system, doctors may ask you to perform specific tasks. They will want to judge any change in your abilities related to strength, memory, and coordination.

Doctors use imaging tests such as CT scans and MRIs to look for a tumor that may be causing symptoms. Blood tests can reveal suspicious findings suggestive of a tumor or the presence of antibodies linked to paraneoplastic syndromes.

Management and Treatment

How are paraneoplastic syndromes managed or treated?

The doctor will attempt to manage the symptoms in an effort to decrease damage. Therapies include:

  • Corticosteroids: Medications that reduce inflammation (swelling)
  • Immunosuppression: Drugs that manage the autoimmune response
  • Intravenous immunoglobulin: Healthy antibodies delivered through a needle into a vein that help destroy the antibodies causing the syndrome
  • Plasmapheresis: A procedure that decreases the numbers of antibodies by removing plasma (liquid) from the blood
  • Physical and speech therapy: Muscle exercises that help people improve functions like speech and movement

Ultimately though, the aim will center on managing the underlying cancer.

What complications are associated with paraneoplastic syndromes?

There is a broad range of complications, some of which are life-threatening. If you have a paraneoplastic syndrome, your doctor will discuss possible related complications with you.

It is important that the management of these symptoms is started as soon as possible because some of the symptoms may be critical. These include high levels of blood calcium or low levels of blood sodium.

Living With

When should I call the doctor in regard to paraneoplastic syndromes?

Contact your doctor immediately anytime you begin to notice any of the symptoms mentioned earlier that do not have an immediate cause. People with symptoms of a paraneoplastic syndrome who have been treated for cancer in the last 5 years should be re-screened for cancer. Re-screening can tell your doctor if the disease has returned.

What questions should I ask my doctor?

  • What is causing my symptoms?
  • Should I be tested for cancer? What tests will I have, and what will these tests tell me?
  • What are my treatment options?

Last reviewed by a Cleveland Clinic medical professional on 04/22/2019.


  • Merck Manuals. Paraneoplastic Syndromes. ( Accessed 4/24/2019.
  • National Institute of Neurological Disorders and Stroke. Paraneoplastic Syndromes Information Page. ( Accessed 4/24/2019.
  • National Organization for Rare Disorders. Paraneoplastic Neurologic Syndromes. ( Accessed 4/24/2019.
  • Cornett PA, Wang S, Friedman LS, Cinar P, Dea TO, McQuaid KR, Meng MV, Ryan CJ. Cancer. In: Papadakis MA, McPhee SJ, Rabow MW. eds. Current Medical Diagnosis & Treatment 2019 New York, NY: McGraw-Hill;

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