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

Few reports indicate that motor neuron diseases may have paraneoplastic origin. A 70 year-old woman suffering from progressive upper motor neuron disease is presented. Laboratory, radiological and neurophysiologic studies were compatible with primary lateral sclerosis. Six years later a routine screening led to the discovery of a breast cancer, suggesting that the upper motor neuron syndrome could be paraneoplastic. So, in female patients with primary lateral sclerosis, a mammography should be recommended to search for breast cancer.