American Board of Internal Medicine (ABIM) Certification Practice Exam

In patients with Myasthenia Gravis, screening for which tumor is recommended?

1. Thyroid tumor

2. Thymoma

3. Lung tumor

4. Hepatic tumor

The correct answer is: Thymoma

In patients diagnosed with Myasthenia Gravis, screening for thymoma is particularly recommended due to the established association between the condition and thymic abnormalities. Myasthenia Gravis is an autoimmune disorder characterized by weakness and fatigue of voluntary muscles, and it is known that around 10-15% of patients with Myasthenia Gravis have a thymoma, which is a tumor of the thymus gland. The thymus plays a crucial role in the immune system, particularly during childhood, and it is believed that abnormalities in this gland can contribute to the pathogenesis of autoimmune disorders, including Myasthenia Gravis. As such, patients with this condition are often screened for thymoma, as identifying and managing this tumor can lead to improved symptoms and overall outcomes. Surgical resection of the thymus, in patients with thymoma, can result in significant improvement or even remission of Myasthenia Gravis symptoms. While thyroid tumors, lung tumors, and hepatic tumors are important considerations in other contexts, they do not have the same direct association with Myasthenia Gravis that thymomas do, making screening specifically for thymoma the most relevant option in this case.