Two cancer patients had extensive spinal cord necrosis at necropsy. One had carcinoma of the breast and the other, carcinoma of the lung. Case 1 was treated by mastectomy, systemic chemotherapy and cranial irradiation, where as Case 2 received local irradiation to the right upper chest and right supraclavicular zone. In both cases, the spinal cord necrosis affected grey and white matter along most of its extent. Neither local nor systemic causes to explain the spinal cord lesion were disclosed at necropsy. It is suggested that these are two new examples of paraneoplastic necrotizing myelopathy. There are 22 such cases in the English language medical literature since 1903.