An 81-year-old man manifested subacute proximal limb weakness, dysphagia, and 25-pound weight loss.  He had stage IV prostate cancer, diagnosed 3 months prior to weakness-onset. Examination revealed mild facial weakness, flaccid dysarthria, moderate-to-severe neck and limb girdle weakness and atrophy. Videofluoroscopic swallow study showed severe oropharyngeal dysphagia with aspiration. CK was 689 U/L (normal 39-108 U/L) at presentation but 6,145 U/L six weeks earlier. Myositis-associated and HMGCR antibodies were negative. EMG showed proximal-predominant myopathic changes with fibrillation potentials. Muscle biopsy revealed several well-demarcated areas of ischemia involving adjacent fascicles. Necrotic fibers were in a similar early stage of necrosis with no macrophagic infiltration and diffuse sarcoplasmic C5b-9 deposition.  A few small collections of perimysial perivascular inflammatory cells were present in the areas of the specimen not affected by ischemia. There was patchy capillary depletion and dilation; some capillaries in areas not affected by ischemia showed complement deposition. Myxovirus resistance protein A (MxA) expression occurred diffusely, especially in necrotic fibers, but without perifascicular predominance. Patient received IVIG 2g/Kg and prednisone 40 mg daily. The limb weakness stabilized while the dysphagia progressed. He expired 3 weeks later.