Imaging Findings associated with P araneoplastic Neurologic Syndromes. BAGGA,S , ESKEY CJ, FADUL, CE D ARTMOUTH -H ITCHCOCK M EDICAL C ENTER , L EBANON , NH. Purpose.
BAGGA,S, ESKEY CJ, FADUL, CEDARTMOUTH-HITCHCOCK MEDICAL CENTER, LEBANON, NH
The purpose of this educational exhibit is to review the clinical manifestations and imaging findings of the most common paraneoplastic neurologic syndromes (PNS).
43-year-old woman presenting with a pelvic mass. CT scan showed
a right ovarian mass that proved to be an ovarian dermoid.
Four years later she presented with mental status changes.
MRI was normal. Anti-MDMA antibodies were positive.
subacute onset of mood changes, hallucinations, memory loss, seizures
small cell lung carcinoma SCLC(40-50%) , testicular carcinoma (20%)
breast cancer (8%), thymoma, lymphoma, teratoma
anti-Hu antibody in half of SCLC cases
anti-Ma-2 antibody in testicular cancer
MRI: The classic finding is hyperintense signal in the medial temporal lobes on FLAIR images, DWI may show restricted diffusion, other areas
that may be similarly involved include inferior frontal lobe, insular cortex and cingulate gyrus. This pattern changes little over time & does not show progression typical of herpes encephalitis.
FDG-PET: hypermetabolismin the medial temporal lobes
herpes encephalitis, post-transplant acute limbic encephalitis,
glial or glioneuronal neoplasm, seizure edema.
Lambert Eaton myastheniform syndrome
gradual onset of lower extremity proximal muscle weakness, fatigue, iaphragmatic weakness; bulbar symptoms milder than myasthenia gravis
later in the course – autonomic symptoms, ptosis, impotence, dry mouth
SCLC, prostate cancer, cervical cancer, lymphoma,adenocarcinoma
Imaging & diagnosis:
No CNS imaging findings. EMG findings (low compound muscle action potential, decremental response with low rate stimulation but incremental response with high rate stimulation) are suggestive.
62-year-old woman with ovarian cancer presenting with ataxia
and diplopia. Her initial MRI (above, left) shows a normal
appearance of the cerebellum, but MRI one year later shows
cerebellar atrophy. Anti-Yoantibody was positive.
Paraneoplastic encephalitis (PE)
subacute onset of memory loss, confusion, seizures
lung cancer, Thymic cancer, Breast cancer
anti-Hu antibody, Anti-CV2, others
MRI: MRI is usually normal. Extralimbic foci of T2 prolongation may be present but no specific pattern has been described.
broad differential diagnosis for nonspecific white matter lesions
62-year-old chronic smoker presenting with proximal lower limb
weakness. CXR interpreted as negative. Anti- VGCC and Anti-Hu
antibodies were positive. CT showed a left lung mass which proved
to be SCLC62 year chronic smoker presented with proximal lower limb
56-year-old woman presenting with seizures. FLAIR and DWI show hyperintense signal in the bilateral medial temporal lobes. CXR shows a right lung mass. Biopsy revealed small lung carcinoma and anti-Hu antibody was positive by Western blot.
Paraneoplastic cerebellar degeneration
PNS is an important but rare group of diseases associated with cancers. The imager should be aware of specific and nonspecific imaging findings of PNS.
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