Rapid Muscle Weakness in a Patient with Anti-TIF1-γ Antibody Positive Dermatomyositis Concurrent with Malignant Tumor

Abstract

A 54-year-old man presented to our hospital with a one-month history of erythema on his face and trunk. During the initial visit, he did not complain of muscle weakness, and blood tests showed a high creatine kinase (CK) level (2,436 U/l). He tested positive for the anti-TIF1-γ antibody and was diagnosed with dermatomyositis. Computed tomography showed liver and multiple lymph node metastases. He was diagnosed with stage IV advanced gastric cancer based on the results of an upper endoscopy. Two weeks after the initial visit, he developed rapid muscle weakness with an increased CK level of 9,083 U/l. Moreover, despite receiving steroid treatment for dysphagia that had developed, his symptoms persisted. Despite chemotherapy, he died four months after the initial visit. In patients with dermatomyositis concurrent with malignant tumor who test positive for antiTIF1-γ antibody, there are relatively less myositis symptoms. However, three patients, including our patient, who had remarkably high CK levels at the initial examination experienced rapid deterioration of myositis-related symptoms, resulting in cancer-stage progression. A literature review suggested that rapid, detailed examination is required to confirm the presence or absence of malignant tumors in patients with dermatomyositis who test positive for anti-TIF1-γ antibody as this condition has a poor prognosis. Skin Research, 21 : 307-313, 2022