PLE-2322

A 42-year-old female is complaining of a dry, nonproductive cough that has lasted for 3 weeks. She has also experienced weight loss and fatigue. She is a chronic smoker with 20 pack years and drinks alcoholic beverages. A CT scan was requested, which showed no suspicious lung lesions but did reveal an incidental finding of thymoma. Which of the following is not associated with thymoma?