<prompt> Which of the following is Not associated with thymoma?HypogammaglobinemiaMyasthenia gravisPolymyositisSIADH  <response>: 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. 