다발성근염은 사지 근위부의 골격근을 대칭적으로 침범하는 원인불명의 자가면역 질환으로, 악성종양과 동반된 사례가 보고되고 있으나 피부 근염에 비해 드물다. 이에 혼합간세포-담관상피암종으로 추정되는 원발성 간암의 신생물딸림증후군에 의한 횡문근융해와 다발성근염 1예를 경험하여 보고하는 바이다.

Polymyositis is characterized by symmetrical proximal muscle weakness, nonsuppurative inflammation of skeletal muscle, elevation of muscle enzyme levels, and abnormality of electromyographical change. Its pathogenesis is unclear. Paraneoplastic syndromes are caused by malignant tumors, although not through direct effects of the primary tumor or its metastases. Several paraneoplastic syndromes, including erythrocytosis, hypoglycemia, and hypercholesterolemia, have been reported in patients with hepatocellular carcinoma. A few cases of polymyositis associated with hepatocellular carcinoma and one case of combined hepatocellular-cholangiocarcinoma associated with polymyositis and chronic hepatitis B virus infection have been reported. Skeletal muscle injuries without trauma, including metabolic myopathy, effects of certain drugs and toxins, infection, electrolyte imbalances, and endocrine disorders, may cause rhabdomyolysis. We present here a case of primary liver cancer associated with polymyositis and rhabdomyolysis. (Korean J Med 2012;82:212-216)