Primary lateral sclerosis with breast cancer, a potential paraneoplastic neurological syndrome.

Few reports indicate that motor neuron diseases may have paraneoplastic ori gin. A 70 year-old woman suffering from progressive upper motor neuron dise ase is presented. Laboratory, radiological and neurophysiologic studies wer e compatible with primary lateral sclerosis, Six years later a routine scre ening led to the discovery of a breast cancer, suggesting that the upper mo tor neuron syndrome could be paraneoplastic. So, in female patients with pr imary lateral sclerosis, a mammography should be recommended to search for breast cancer.