This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Not a posterior mediastinal tumor - 
Select and explain. 
A. Neurofibroma, B. Lymphoma, C. Thymoma, D. Gastroenteric cyst
C: Thymoma
Answer: C: Thymoma 
Explanation: None