[Nationwide survey of necrotizing myelopathy associated with malignancy in Japan].

Twenty-two cases of transverse myelopathy associated with malignancy were collected in nationwide survey in Japan. Paraneoplastic necrotizing myelopathy (PNM) was suspected in 9 of them and 8 cases were diagnosed as radiation myelopathy (RM), clinically and pathologically. Other 5 cases had different causes of transverse myelopathy. In comparison with PNM and RM, malignant lymphoma, flaccid paraplegia and sphincter dysfunction were highly associated in the patients with PNM. On the other hand, lung cancer, spastic paraplegia, abnormality in spinal MRI and dysesthesia in legs as an initial symptom were prevalent in the cases of RM. Six cases of them were compared pathologically. Although all cases had no metastasis of malignant cells, five cases of PMN showed acute and chronic necrosis and rarefaction of spinal cord with or without perivascular cuffing. One case of RM had focal spinal cord atrophy and no lymphocytes infiltration. Immunohistochemically, herpes simplex virus type 2 (HSV2) infection in spinal cord was shown in the 2 cases of the necrotizing myelopathy. Virus infection such as HSV2 could be one of causes of PNM and virological study must be done in the cases of necrotizing myelopathy associated with malignancy.