Occult small cell lung cancer associated with paraneoplastic neurologic syndrome: case report.

Cancer is often associated with paraneoplastic syndromes, which may be misinterpreted. We report a case of a patient with occult small cell lung cancer that was initially compounded by clinical features of a paraneoplastic neurologic syndrome. The presence of antineuronal antibodies and positron emission tomography scan guided the search for the underlying tumor. Following chemo-radiotherapy the patient showed no evidence of disease for the next 18 months, whereas only a slight improvement in the neurologic disorders was observed. The course of the small cell lung cancer was very indolent and the paraneoplastic neurologic syndrome did not worsen with the use of cisplatin.