Which thymic finding is NOT typically associated with myasthenia gravis?

• A. Thymic hyperplasia
• B. Thymoma
• C. Thymic aplasia
• D. None of the above

Answer: (C)

The link between thymic pathology and myasthenia gravis centers on how the thymus influences T‑cell development and autoimmunity against the neuromuscular junction. In MG, thymic hyperplasia or a thymoma are the classic thymic findings because they can promote production of autoantibodies against acetylcholine receptors. Thymic hyperplasia shows expanded lymphoid tissue with germinal centers, while thymoma is a thymic tumor; both are well described in MG patients and are thought to drive the autoimmune process.

Thymic aplasia, however, is a developmental failure of the thymus seen in conditions like DiGeorge syndrome and typically leads to T‑cell immunodeficiency rather than autoimmunity. It does not fit the pattern seen in MG, so thymic aplasia is the finding not typically associated with myasthenia gravis.