SUN-453 Isolated Psychosis As New Onset Cushing Syndrome

Abstract Disclosure: M. Luna Cuadros: None. S. Haddady: None. Introduction: Although Cushing Syndrome manifestations can be florid and severe, isolated psychiatric features are less common as main clue for diagnosis. Clinical case: 31-year-old female without medical history presented for agitation, paranoia and disorganized behavior. Physical exam was unrevealing except for overweight. Workup for toxic/metabolic causes included CT Abdomen that showed a 2.6cm right adrenal mass and Brain MRI showed a 4mm hypoenhancing focus in the pituitary. Hormonal workup showed AM cortisol 15.6 ug/dl, ACTH <5 pg/ml, DHEA-S 19.5 mcg/dl raising concern for ACTH independent Cushing Syndrome. Prolactin, IGF-1, free T4, aldosterone/renin and plasma metanephrines were normal. Further testing revealed elevated LNSC 0.42 and 0.5 mcg/dl, Dexamethasone suppression test: cortisol 16 ug/dl, dexamethasone 375 ng/dl. Patient was started on aripiprazole and evaluated by Surgery. Patient had right laparoscopic adrenalectomy for ACTH independent Cushing Syndrome. Given possibility of temporary adrenal insufficiency due to atrophy of remaining adrenal gland, patient was started on perioperative steroids with taper to hydrocortisone 20mg qam and 10mg qpm. On follow up, reported that hallucinations have resolved, now on hydrocortisone 20mg qam and 5mg qpm with plans to reevaluate with cosyntropin stimulation test. Conclusion: Psychiatric features in Cushing Syndrome can present as prodrome, during the course or even after resolution. A thorough endocrine workup can determine CS cause in the setting of adrenal and pituitary lesions. Presentation: Sunday, July 13, 2025