Thymic Hyperplasia


CT scanning may show symmetrical, diffuse enlargement of the thymus. When the enlargement is asymmetrical, it may mimic a thymoma; thymoma should be considered in the differential diagnosis.[1] 
About two thirds of patients with myasthenia gravis have thymic hyperplasia; 25-50% of these patients are likely to have a normal thymus on CT scanning. Histologic analysis of the thymic medulla reveals numerous lymphoid follicles with active germinal centers.

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