SUN-168 Case Series of ACTH-Secreting Pheochromocytoma: Diagnosis and Management

INTRO ACTH-secreting pheochromocytoma is rare, posing challenges in diagnosis and management. Here we report two cases with different presentations and pre-operative approaches. CASES Patient 1 A 59 yo female who presented for basal cell carcinoma resection experienced hypertensive crisis intra-op and NSTEMI due to stress cardiomyopathy. The patient reported spells of palpitations, diaphoresis, tremors and pallor since 2015. She had elevated plasma metanephrine (M) 19.4 (0-0.49nmol/L), normetanephrine (NM) 24.7 (0-0.89nmol/L), 24-hour urine M 18711 (30-180mcg) and NM 11897 (128-484mcg). Imaging demonstrated a 5.6 x 5.5 x 5.8cm left adrenal mass. After pre-operative alpha and beta blockade, patient underwent left adrenalectomy. Pre-op 24-hour urine cortisol was checked as part of secondary HTN evaluation and found to be elevated at 219 (3.5-45mcg). She did not have any features of Cushing’s and this was initially felt to be an appropriate stress response. Due to persistent post-op hypotension and a low 10PM random cortisol level of 3.4mcg/dL, which was inappropriate given patient’s clinical status, hydrocortisone was started with subsequent hemodynamic improvement. Our suspicion was that she had an ACTH-secreting pheochromocytoma, which would have resulted in hypercortisolism pre-op, and secondary AI post-op. Pathology report later confirmed ectopic ACTH production with 25% cells positive with immunostaining. Patient 2 A 48 yo female was admitted for hypertensive urgency with symptoms of palpitations, facial and abdominal swelling, easy bruising and proximal muscle weakness. Her labs showed elevated 24-hour urine epinephrine 115 (0-20mcg), norepinephrine 366 (0-135mcg), plasma M 288 (0-62pg/mL) and NM 475 (0-145pg/mL), and an AM cortisol was 47.9mcg/dL. Aldosterone and renin levels were <1ng/dL and 0.775ng/mL/hr. Imaging revealed 3.4 x 3.1cm right adrenal mass with portal venous phase of 53 HU and no washout. AM cortisol level post 1mg dexamethasone was 62.6mcg/dL with an ACTH level of 222pg/mL. An ACTH-producing pheochromocytoma was suspected. Despite progressive uptitration of alpha and beta blockade, her BP remained poorly controlled. Her blood glucose also increased to 300s range. Ketoconazole 400mg BID was subsequently added to the regimen with rapid and marked improvement in BP and glycemic control. She underwent right adrenalectomy. Post-op plasma M, NM and ACTH were <0.20nmol/L, 0.36nmol/L and <5pg/mL. DISCUSSION Within the past 6 months, we have seen 2 cases of ACTH-secreting pheochromocytoma with different clinical symptoms and pre-op courses. Ectopic ACTH secretion may not cause classic Cushingoid features as in patient 1. Failure to recognize ectopic ACTH pre-op can lead to post-op complications such as AI. Patient 2 demonstrates that treatment of the hypercortisolemia may be necessary in order to adequately control BP and glucose levels prior to surgery.