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: Medicine
[{'content': 'Which of the following is not associated with thymoma: \nSelect and explain. \nA. Red cell aplasia, B. Myasthenia gravis, C. Hypergammaglobulinemia, D. Compression of the superior mediastinum', 'role': 'user'}, {'content': "Answer: C \nExplanation: Thymoma associated autoimmune diseases are: ? Myasthenia gravis ? Phemphigus ? Systemic lupus erythematosus ? Pure red cell aplasia ? Hypogammaglobulinemia Ref: Illustrated Dictionary of Immunology By M.P. Arora, Pages 257-258 ; Cancer and Autoimmunity By Yehuda Shoenfeld, M. Eric Gershwin, Page 249 ; Harrison's Principle of Internal Medicine, 16th Edition, Page 1946", 'role': 'assistant'}]