SAT-263 A Vicious Cycle of Hypercortisolism - Cyclical Cushing’s Syndrome

Abstract

Background: Cyclical Cushing’s syndrome (CS) is described as periods of excess cortisol secretion interspersed with low or normal cortisol. The generally acceptable criteria for diagnosis is demonstration of 3 peaks and 2 troughs in cortisol secretion but, in practice, patterns and duration of cycles are unpredictable and can present a significant diagnostic challenge. Here, we present a case series of three patients who did not meet the published criteria but had pathological confirmation of ACTH-dependent CS. Clinical Case: Two women (A: 30 year-old, B: 40 year-old), and one man (C: 30 year-old) presented to the Pituitary Center for second/third opinions regarding CS. All patients had significant central weight gain. Patient A described cycles of rapid weight gain and loss, fluctuating facial and leg swelling, anxiety and darkening of stretch marks or scars punctuated with episodes of fatigue, lightheadedness and nausea. Patients B and C reported cyclical leg swelling, facial redness and acne. These patients had additional clinical signs of Cushingoid facies, dorsocervical and supraclavicular fat pads. Patient C had violaceous striae.Multiple tests for CS were performed: 1 mg overnight dexamethasone suppression test, two midnight salivary cortisols, and 24h urine free cortisol (UFC). All testing was normal, with a few exceptions. Patient A had an isolated midnight salivary cortisol elevated to 0.426 (<0.112 ug/dL). Patient C had two mildly elevated 24h UFC collections of 1.4 times upper limit of normal corresponding with his cycles of peripheral edema and acne. Patient B had completely negative testing. In all 3 patients, ACTH levels were not suppressed but also not elevated. Random serum DHEA-S levels were elevated in patients A and B.Patients A and C were found to have possible pituitary microadenomas on MRI with dynamic contrast. Patient B’s MRI was negative but inferior petrosal sinus sampling revealed a markedly elevated tumoral level of ACTH of >62,500 pg/mL with CRH stimulation. All 3 patients underwent endoscopic transsphenoidal resection by an expert pituitary surgeon with no post-operative complications in patients A & B, but development of partial diabetes insipidus in patient C. In patients A & C, pathology revealed corticotroph hyperplasia while patient B was found to have a corticotroph adenoma. Patients A & B persisted to have symptoms of hypercortisolism, opted to undergo bilateral adrenalectomy and pathology showed diffuse adrenocortical hyperplasia for both. Conclusion: Cyclical CS is likely underdiagnosed because of difficulty in obtaining biochemical confirmation even with strong clinical suspicion of CS. DHEA-S has a long half-life as well as minimal diurnal variation, and could be an additional clue in patients with suspected pituitary source of cyclical hypercortisolism. Ultimately, clinical concern should drive further diagnostic imaging and management.