Abstract
Growth hormone has a strong role in stimulation of the thymus. We report a case of thymic hyperplasia due to excess endogenous growth hormone in the setting of acromegaly. Acromegaly often presents with systemic manifestations that may be confused with a systemic hematologic malignancy or infection, especially if an anterior mediastinal mass is present but unrecognized as a benign thymic hyperplasia. It is important for radiologists to be aware of this association between growth hormone and thymic stimulation because it may increase confidence diagnosing thymic hyperplasia in this setting, and avoid unnecessary mediastinal biopsy or surgery.