Report of an autopsy case of colon cancer with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a degenerative disease involving both upper and lower motor neurons and the pathogenesis of this disorder is still unknown. To date, few reports have suggested that motor neuron diseases may have a paraneoplastic origin. However, it is still under discussion whether ALS occurring in cancer patients is paraneoplastic. A 60-year-old man with rectal cancer (Stage IV) having multiple lung, liver and para-aortic lymph node metastases underwent anterior resection of the rectum as palliative surgery. He was referred to our hospital for adjuvant chemotherapy. Lung and lymph node metastases decreased after 2 courses of chemotherapy using CPT-11 and 5-FU/LV but liver metastases were enlarged, following up increase in CEA. Thereafter, he suffered from muscle weakness in hands, arms, and legs and results of neurophysiologic studies were compatible with primary lateral sclerosis (ALS). For second line chemotherapy, he was treated with low-dose CDDP/5-FU over 6 courses. As a result, the size the of metastatic lesions markedly reduced and CEA was decreased to the normal level. Although significant tumor reduction was observed, his neurological symptoms rapidly progressed. He died of aspiration pneumonia 8 months after onset of the disease. Autopsy revealed that his neuropathological findings were compatible with ALS, and it was thought to be the primary cause of death in the because of absence of cancer progression. In this case the neurological syndrome was not affected by cancer therapy. Thus our case does not support the hypothesis that ALS in associated with cancer and the relationship between both disorders remains uncertain.