A Second Look at Cushing Disease: Hypercortisolism Recurrence From Another Gland

Cushing disease (CD) is the most common form of adrenocorticotropin (ACTH)-dependent Cushing syndrome (CS), whereas unilateral adrenal adenoma is the most common cause of ACTH-independent CS. However, the occurrence of different subtypes of CS in a single individual is very rare. We present a case of a 44-year-old woman with distant histories of left adrenalectomy for an adrenal adenoma and total thyroidectomy following the diagnosis of papillary thyroid carcinoma. She was later diagnosed with CD, achieving disease remission after pituitary surgery, but subsequently developed adrenal CS from the remaining right adrenal gland. After discussing the potential advantages and drawbacks of another adrenalectomy to remove her right adrenal gland, the patient declined surgery and opted for medical management. After 7 years of imaging follow-up studies, her right adrenal adenoma has remained stable in size and she is biochemically controlled on low-dose osilodrostat therapy. Our case emphasizes the importance of recognizing the rare occurrence of successfully treated CD followed by the recurrence of CS from a different gland, and the adoption of management strategies tailored to each individual patient's preferences.