Polymyositis as a paraneoplastic manifestation of hepatocellular carcinoma

A case of hepatocellular carcinoma associated with polymyositis is reported. A 70-year-old man noticed muscular weakness mainly in the proximal limb muscles. The clinical course, a raised level of serum creatine kinase and electromyographic findings suggested polymyositis, and the pathological findings on muscle biopsy were compatible with this diagnosis. Computed tomography of the upper abdomen revealed a mass lesion in segment VII and VIII of the liver, which was diagnosed pathologically as hepatocellular carcinoma. The patient underwent systematic resection of segment VII and the dorsal part of segment VIII of the liver. After surgery, the weakness improved and the serum creatine kinase level normalized without medical treatment for the polymyositis. The relief of neurological symptoms and signs after complete resection of the tumor strongly suggests paraneoplastic polymyositis, which has been described only rarely in association with hepatocellular carcinoma.