[Case of systemic myositis and subacute sensory neuropathy concomitant with signet-ring cell carcinoma]

A 72-year-old woman referred to our hospital because of slowly progressive (over 2 years) muscle weakness and paresthesias of the lower limbs. On neurological examination, weakness and muscle atrophies were noted in the distal upper limbs as well as the proximal lower limbs. She had also paresthesias of the legs. The level of creatinine phosphokinase (CK) was 126 IU/l. The magnetic resonance imaging demonstrated gadolinium enhancement of the nerve roots at the L4-S2 vertebrate levels. Nerve conduction study showed decreased compound muscle action potential and motor conduction velocity of tibial and peroneal nerves. Biopsy of the left biceps brachii muscle showed variations in fiber size, endomysial mononuclear cell infiltration and the findings like a rimmed vacuole. Although almost of her findings were in accord with clinical features of inclusion body myositis, strong inflammatory cellular influences allowed us to administer corticosteroid therapy. Because her weakness was well responded to steroid therapy, polymyositis was considered as differential diagnosis. Then, further examinations were investigated to search any occult neoplasm, and detected the early gastric cancer. Total gastrectomy was performed later, and the pathological diagnosis was made as a signet-ring cell carcinoma. To our knowledge, this is the first report of systemic myositis and subacute sensory neuropathy concomitant with signet-ring cell carcinoma. These symptoms might be occurred as a result of paraneoplastic syndrome associated with satellite effects of the signet-ring cell carcinoma.