ORIGINAL ARTICLEOccult Malignancy in Patients With Suspected Paraneoplastic Neurologic Syndromes: Value of Positron Emission Tomography in Diagnosis
Section snippets
PATIENTS AND METHODS
After approval by the Mayo Clinic Institutional Review Board, the nuclear medicine electronic database at Mayo Clinic's site in Rochester, MN, was queried for PNS as an indication for PET. A total of 107 patients were identified in the database from January 1, 2000, to July 31, 2006.
RESULTS
Of the 107 patients identified from the PET database, 104 met the inclusion criteria.15 Three patients were excluded because 1 had metastasis to the brain and 2 did not have a final diagnosis of PNS. Baseline characteristics of all the patients are described in Table 1. Seventy-three patients had a positive result for at least 1 paraneoplastic antibody, and 31 had a clinical diagnosis without a detectable paraneoplastic antibody. PET results were positive in 24 patients, 17 of whom had a
DISCUSSION
Patients with suspected PNS present a diagnostic dilemma because of the difficulty in detecting a suspected occult malignancy with conventional testing. Although PET has been recommended and used to detect occult malignancies in this patient population, its diagnostic utility has not been well defined.12
We have scrutinized the clinical utility of PET in patients with suspected PNS. Data suggest that PET has a better NPV (88%) and therefore is a better diagnostic tool to rule out occult
CONCLUSION
PET is substantially more sensitive than CT for detecting occult malignancy in patients with suspected PNS. Occult malignancy was detected only in patients with PNS who had a positive test for autoantibody. Patients with suspected PNS and no detectable malignancy should be followed up every 6 to 12 months for a period of at least 5 years as recommended by the European Federation of Neurological Societies. The utility of follow-up CT or PET in these patients could not be determined because of
REFERENCES (18)
- et al.
Autoimmune paraneoplastic cerebellar degeneration: immunohistological localization of antibody-binding sites
Clin Neurol Neurosurg
(1995) - et al.
Regression of small-cell lung carcinoma in patients with paraneoplastic neuronal antibodies
Lancet
(1993) - et al.
Paraneoplastic syndromes involving the nervous system
N Engl J Med
(2003) Onconeural antigens and the paraneoplastic neurologic disorders: at the intersection of cancer, immunity, and the brain
Proc Natl Acad Sci U S A
(1996)- et al.
Paraneoplastic antibodies coexist and predict cancer, not neurological syndrome
Ann Neurol
(2004) - et al.
Detection of autoantibodies to the BTB-kelch protein KLHL7 in cancer sera
Scand J Immunol
(2006) - et al.
Autoantibodies in paraneoplastic syndromes associated with small-cell lung cancer
Neurology
(1988) - et al.
Guidelines on the detection of paraneoplastic anti-neuronal-specific antibodies: report from the Workshop to the Fourth Meeting of the International Society of Neuro-Immunology on paraneoplastic neurological disease, held October 22-23, 1994, in Rotterdam, The Netherlands
Neurology
(1995) Paraneoplastic neurologic disorders: windows into neuronal function and tumor immunity
Arch Neurol
(2004)
Cited by (0)
These data were presented as a poster at the 12th World Conference on Lung Cancer; Seoul, South Korea; September 2-6, 2007.