Dual Adenomas: Detection of Cushing’s Syndrome of Adrenal Origin During Evaluation of Pituitary Macroadenoma

Abstract

Cushing’s syndrome is a rare and often severe disease associated with increased mortality and major metabolic complications with cardiovascular disease as the main cause of death. Adrenal masses are most often found by radiographic studies or autopsy as incidentalomas. The prognosis of Cushing’s syndrome is mainly affected by the difficulties in timely diagnosis and treatment of the disease, which remain a challenge due to its nonspecific presentation and multitude of etiologies. Herein, we present an atypical case of adrenal Cushing’s syndrome unveiled by the workup of a nonfunctioning pituitary macroadenoma. A 62 year-old woman presented with new intermittent headaches and worsening vision changes for the past year. She was found to have a large sellar mass measuring 2.7 x 2.4 x 3.0 cm invading the right cavernous sinus with displacement of the optic chiasm on brain magnetic resonance imaging (MRI). In the interim to neurosurgical evaluation, lab work performed to assess pituitary function showed an elevated late night salivary cortisol at 0.200 UG/DL (0.010–0.090 UG/DL range). Low early morning ACTH and elevated late night salivary cortisol, dexamethasone suppression test and 24 hour urine cortisol were observed and confirmed with repeat studies. These findings warranted a computed tomography (CT) adrenal mass protocol which revealed a left adrenal lesion consistent with a lipid rich adenoma measuring 4.9 x 3.5 x 4.1 cm in size. Subsequent urine catecholamines and metanephrines were within normal limits. The patient was admitted for transphenoidal pituitary resection with perioperative stress dose corticosteroids, but was only able to achieve partial resection due to large tumor size. Post-operatively the patient did well on a quick corticosteroid taper down to hydrocortisone 15 mg in AM and 5 in afternoon with hope to wean in the near future. Post-operative workup showed ACTH 4.6 pg/mL (7.2 – 63.3 pg/mL) and 8 am cortisol 24.7 MCG/DL (6.2–19.4 MCG/DL) which suggests autonomous adrenal secretion of cortisol. Once the patient has recovered from her partial pituitary resection she will be referred to general surgery for adrenalectomy. This case provided a review of a classic pituitary macroadenoma workup with an interesting twist to Cushing’s etiology as the cause was not from the pituitary as originally thought.