Thyrotroph Hyperplasia Caused by Severe Primary Hypothyroidism Leading to Adrenal Crisis.

Thyrotroph hyperplasia is commonly present but remains largely undiagnosed in primary hypothyroidism. It is easily reversible with thyroid replacement therapy. If imaging is performed prior to biochemical evaluation, then patients may undergo pituitary surgery unnecessarily. We present the case of a 30-year-old man with thyrotroph hyperplasia caused by profound primary hypothyroidism leading to hypopituitarism that resolved after levothyroxine replacement therapy. We will discuss the current literature regarding pituitary hyperplasia in primary hypothyroidism in adults.