SUN-394 A Curious Case of Cushing's

Abstract

Background: Cushing’s Disease and Syndrome is a rare condition that can greatly impact a person’s health. Usually, it is easy to determine the cause of cortisol excess. However, when adrenal and pituitary examination fail to reveal a source, devising a management strategy can prove difficult. Clinical Case: A 27-year-old male with no significant PMH presented originally to an urgent care clinic with non-specific complaints, gaining weight, back spasms weakness, and chest pain. He was hypertensive and had significant abdominal stria. He was referred to endocrinology and found to be very cushingoid. Initial laboratory testing found a random cortisol 29.3 mcg/dl and ACTH was 227.4 pg/ml. Salivary cortisol was elevated at 0.526 ug/dl. A 24 hour urinary cortisol was 800 ug/24 hours. An 8mg dexamethasone suppression test was performed which did not suppress cortisol (22.2 mcg/dl). An MRI of his pituitary was read as normal. A chest CT showed a healed 2nd rib fracture but otherwise unremarkable. CT of abdomen and pelvis showed no adrenal mass and demineralization of the bone especially at the spine. The patient then underwent inferior petrosal sinus sampling which showed no step up from peripheral to central. At this point the he was started on Ketoconazole which was titrated up to 800mg mg/day. The patient was subsequently admitted multiple times to the hospital for cellulitis of his lower left extremity. A skin biopsy of his lower extremity revealed erythema nodosum. During one of these admissions he developed adrenal insufficiency which was treated with hydrocortisone replacement. Gallium-68 somatostatin receptor positron emission tomography was performed to determine the source of ACTH. It revealed a nonspecific subcentimeter nodular focus of tracer uptake just lateral to the right atrial appendage. Since being on the ketoconazole the patient has experienced significant improvement in his blood pressure, strength and abdominal striae. Conclusion: This unusual case provides valuable insight into the process of diagnosing Cushing’s Disease and Syndrome. While this process is usually straight forward, if an ectopic source of elevated ACTH remains unknown, the case can require a very substantial investigation. Because of the unique complexity of this case, it allows for a useful review of the physiology and pathophysiology of the pituitary adrenal axis.