A case of anti-TIF1-γ-positive amyopathic dermatomyositis associated with gastric cancer

A 63-year-old Japanese male visited our hospital complaining of a 3-month history of erythema on his chest and back. Initial physical examinations revealed pruritic erythema on his cheek, V-neck area, posterior neck, and shoulders with Gottron's sign and nailfold telangiectasia. He had no muscle pain or weakness. Histopathologically, an interface change was evident with lymphocytic infiltration. Laboratory examinations showed positivity for anti-transcriptional intermediary factor (TIF)1-γ antibody, but other data were negative or within normal ranges including anti-Mi-2 antibody, anti-Jo-1 antibody, KL-6, creatine phosphokinase, and aldolase. Radiographic examinations showed no pulmonary abnormality. He was finally diagnosed as having amyopathic dermatomyositis. Because of a frequent association between malignancies and positivity for anti-TIF1-γ antibody, further extensive examinations were carried out and early gastric cancer was discovered. After starting the systemic administration of prednisolone (30 mg/day), his gastric cancer was removed successfully and the cutaneous lesions were subsequently completely cured. The systemic steroid treatment was tapered and terminated without any recurrence of amyopathic dermatomyositis. Anti-TIF1-γ antibody also became undetectable.