Approximately what percentage of MG patients have a thymoma?

• A. 0%
• B. 10%
• C. 25%
• D. 50%

Answer: (B)

Thymic abnormalities are linked to myasthenia gravis, with the thymus playing a role in driving the autoimmune response at the neuromuscular junction. In MG, thymoma occurs, but it is only a minority of cases—roughly one-tenth of patients. Thymic hyperplasia is more common, especially in younger individuals, so the thymus is often involved in MG even without a tumor. Therefore, the best approximate figure is around 10%. Options like zero percent would ignore the established thymic association, while 25% or 50% would overstate how often thymoma accompanies MG.