Presentation: About 40% of thymomas cause symptoms due to compression of anterior mediastinal structures. The symptoms include dyspnea, persistent cough, chest pain, fever, night sweats, and weight loss. Between 30% and 45% of thymomas are diagnosed during the evaluation of patients with myasthenia gravis. They present with muscle weakness, fatigue, drooping eyelids, diplopia, and dysphagia. The image shows a multilobulated, pink-tan tumor that was diagnosed as a thymoma. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission.