How do you diagnose a thymoma?

Imaging +/- biopsy. Chest ct scan is the main modality. Additional tests can be used and occasionally a needle biopsy may be needed. Frequently the diagnosis is confirmed only after resection.
Myasthenia gravis. Often thymomas present as a result of an associate disease call myasthenia gravis (mg). Mg is classically diagnosed with symptoms that begin with ocular weakness leading to blurry vision. This can progress to "bulbar" symptoms which involve your ability to swallow and further more it can lead to generalize body muscle weakness. These symptoms can be a tip off that a pt may indeed also have a thymoma.