paraneoplastic syndrome
Pronunciation: para-neo-PLAS-tic
Neurological dysfunction caused by immune response to cancer, not direct tumor effects.
Full Definition
Paraneoplastic syndrome refers to a collection of neurological symptoms and signs that result from the immune system's response to cancer, rather than from direct effects of tumor mass, metastasis, or treatment. These syndromes occur when antibodies or T-cells directed against tumor antigens cross-react with normal nervous system proteins that share similar epitopes (molecular mimicry). Common paraneoplastic neurological syndromes include limbic encephalitis, cerebellar degeneration, and Lambert-Eaton myasthenic syndrome. The neurological symptoms often precede cancer diagnosis, sometimes by months or years, making recognition of these syndromes crucial for early cancer detection. Specific antibodies such as anti-Hu, anti-Yo, and anti-CASPR2 are associated with particular syndromes and tumor types. Treatment typically involves addressing the underlying malignancy combined with immunosuppressive therapy.
Usage
Usage note: Distinguish from direct tumor effects and specify the type of neurological syndrome when possible.
In Context
- "The patient's limbic encephalitis was diagnosed as a paraneoplastic syndrome associated with lung cancer." — Clinical case report
- "Screening for occult malignancy is indicated in cases of suspected paraneoplastic syndrome." — Diagnostic guideline