This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
Thymoma associated with 
Select and explain. 
A. Myasthenia gravis, B. Polycythemia, C. Ectopic ACTH, D. Polyaentis nodosa
A: Myasthenia gravis
Answer: A: Myasthenia gravis 
Explanation: * Thymus is abnormal in 75% patients with MG. 65% - hyperplastic, 10%- thymic tumours or thymomas Ref Harrison20th edition pg 2345