Paraneoplastic syndromes can sometimes occur alongside many forms of brain cancer. They are caused when the immune system, in addition to attacking cancer cells, begins attacking normal, healthy cells of the nervous system, including those in parts of the brain, spinal cord, peripheral nerves or muscles. The immune system may also attack other organ systems, such as the endocrine system or the skin.
So, what causes the immune system to attack these healthy cells? Cancerous tumors can cause certain substances – such as hormones or antibodies – to enter the bloodstream. It is these substances that can cause abnormal problems. For instance, as the body’s immune system releases a certain antibody to attack a tumor, that type of antibody might also interact with brain tissue and result in impaired vision.
Symptoms of paraneoplastic syndromes
Depending on where the nervous system is being attacked, a variety of symptoms can occur. Problems can arise with movement and coordination, sensory perception, memory or thinking, or even sleeping. For example, symptoms could include issues like difficulty walking, slurred speech, seizures or loss of fine motor skills. If other organ systems are attacked, various other symptoms may be present, such as low blood sugar, hypertension or diarrhea.
Types of paraneoplastic syndromes
"Paraneoplastic syndrome" is an umbrella term in that there is actually a wide range of these syndromes.
The endocrine system includes organs such as the pituitary gland and hypothalamus that produce hormones. Some examples of paraneoplastic syndromes affecting the endocrine system include Cushing syndrome, hypercalcemia, hypoglycemia and carcinoid syndrome.
Paraneoplastic syndromes of the nervous system cause dysfunction of the brain, spinal cord, nerves or muscles, and include syndromes such as cerebellar degeneration, limbic encephalitis, stiff person syndrome, peripheral neuropathy and myelopathy.
Sometimes the immune system attacks blood or bone marrow cells, causing hematological paraneoplastic syndromes such as anemia, polycythemia and granulocytosis. Syndromes such as these may impact blood cell production in the bone marrow or a reduction or increase in white or red blood cells or platelets.
The skin can also be affected by paraneoplastic syndromes. These syndromes include dermatomyositis (causing skin rash and muscle weakness), necrolytic migratory erythema (causing a red, blistering rash that spreads across the skin) and pyoderma gangrenosum (causing tissue to become necrotic).
Moffitt Cancer Center
To learn more about paraneoplastic syndromes and their causes, or to consult with an oncologist about symptoms you may be experiencing, call 1-888-663-3488 or complete our new patient registration form online. Referrals are never required to visit Moffitt.