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: Pathology
Which of the following is Not associated with thymoma? 
Select and explain. 
A. Hypogammaglobinemia, B. Myasthenia gravis, C. Polymyositis, D. SIADH
D: SIADH
Answer: D: SIADH 
Explanation: Thymoma is the commenest anterior mediastinal tumor which causes symptoms due to compression on the mediastinal structures. It is associated with the following paraneoplastic syndromes:
• Myasthenia gravis (most common)
• Acquired hypogammaglobulinemia
• Pure red cell aplasia
• Graves disease
• Pernicious anemia
• Dermatomyositis-polymyositis
• Cushing syndrome.