Abstract
Synchronous multiple primary cancers are relatively uncommon and synchronous multiple cancers in coexistence with dermatomyositis (DM) are extremely rare. In the present study, we report a case of a 64-year-old male with nasopharyngeal undifferentiated non-keratinizing carcinoma and cardia adenocarcinoma which were diagnosed synchronously. In addition, suspected DM was diagnosed during the course of chemotherapy. The symptoms of DM were exaggerated even when methylprednisolone while administered. The patient succumbed to nutritional deterioration four months following his initial admission. In the present study, the etiologies of multiple primary cancers are discussed and a brief review of the literature on the correlation between malignance and DM was conducted.