Cushing's Disease Treatment

A 19-year-old woman was referred to Dr. Adriana Ioachimescu for evaluation following an abnormal 1-mg dexamethasone suppression test. She started to experience weight gain, hirsutism and oligomenorrhea at age 16. At that time, she was diagnosed with type 2 diabetes, which was not controlled, despite oral medications and 200 units of insulin daily. A few months before her initial visit to the Emory Pituitary Center, the patient experienced a hip fracture and required surgery. On examination, it was discovered that she had typical Cushing’s stigmata, severe proximal myopathy and depression. She was unable to walk without assistance.

Laboratory testing results were remarkable for hypokalemia, elevated serum cortisol and adrenocorticotropic hormone (ACTH) levels, and elevated bedtime salivary cortisol (15 times above normal). A high-dose dexamethasone suppression test was equivocal. Magnetic resonance imaging (MRI) of the pituitary gland showed no abnormalities. The patient was scheduled for a corticotropin-releasing hormone (CRH) test; however, she was unable to keep the appointment due to MRSA sepsis/perineal cellulitis.

Dr. Ioachimescu started the patient on ketoconazole, which she took for three months, along with multiple courses of antibiotics, during which her diabetes and hypokalemia improved. Once the MRSA infection cleared, she underwent inferior petrosal sinus sampling at Emory University Hospital, which showed a 5:1 central-to-periphery gradient on the right side. A computed tomography (CT) scan of the neck, chest, abdomen and pelvis and an octreoscan did not identify a tumor.

Dr. Oyesiku performed 3-D transsphenoidal endoscopic surgery to remove the tumor causing Cushing’s disease, and her postoperative cortisol on postoperative day three was low at 1.4 mcg/dL. The patient did not experience postoperative endocrine or neurosurgical complications. She required hydrocortisone postoperatively and lost 19 kg in the first three months following the procedure. Her appearance, mood and muscle strength improved significantly.

This case illustrates challenges related to diagnosis of Cushing’s disease in the setting of multiple complications. An accurate diagnosis was made only after inferior petrosal sinus sampling. Treatment with transsphenoidal surgery was successful, despite a lack of tumor identification by preoperative imaging. At the Emory Pituitary Center, Cushing’s disease has a 92% rate of remission at three months following surgery. These statistics are based on the electronic database review of almost 70 patients with Cushing’s disease operated on by Dr. Oyesiku over a period of 15 years. Based on Dr. Ioachimescu’s research, cortisol levels lower than 5 mcg/dL in the first two postoperative days are predictive of surgical success, but do not correlate with recurrence rate.