Abstract
Dermatomyositis is an autoimmune disease characterized by inflammation of the muscles and distinctive skin rashes. Although anti-TIF1- γ antibody-positive dermatomyositis is frequently associated with malignancies, co-occurrence with oral cancer is exceedingly rare. We report a case in which a 65-year-old male was associated with anti-TIF1- γ antibody-positive dermatomyositis during treatment for primary intraosseous carcinoma of the right mandible. After remission from lung cancer treated with chemotherapy, the patient was referred to our department in May 2023 since PET-CT imaging revealed abnormalities in his right mandible. After examination, the diagnosis was primary intraosseous cancer in the right mandible and metastasis to the right cervical lymph node. He underwent a right hemimandibulectomy, modified radical neck dissection, and plate reconstruction under general anesthesia. He presented severe dysphagia, muscle weakness, and erythema 44 days after surgery and was diagnosed with dermatomyositis, and high-dose steroid therapy was initiated. The postoperative pathological report showed positive margins at the primary tumor site, and high-dose cisplatin combined with radiation therapy was administered. Upon discharge, the dysphagia persisted, however there was a trend toward improvement in muscle weakness and skin symptoms, leading to transfer to another hospital for rehabilitation. He passed away suddenly due to myocardial infarction at the same hospital 180 days after surgery.
