Abstract
Thymoma can present with paraneoplastic-autoimmune neuromuscular disorders, including polymyositis, dermatomyositis, and granulomatous myositis. Rarely, concomitant subclinical myasthenia gravis (MG) can be a diagnostic dilemma and cause deleterious outcomes regarding missed or delayed diagnosis. We report a patient presented with thymoma-related inflammatory myopathy and positive acetylcholine receptor antibody without evident MG clinic.