MON-375 Chronic Hypertension Causing by Adrenal Medulla Hyperplasia Mimicking the Presentation of Pheochromocytoma

Background: Well-known causes of endocrine hypertension include primary hyperaldosteronism, pheochromocytoma, Cushing’s syndrome, etc. (1). In the international literature, adrenal medullar hyperplasia (AMH) has not been familiar for the clinicians as a cause of hypertension, and it possibly leads to misjudgment in the clinical treatment/outcomes. We reported an unusual case of resistant and prolonged hypertension caused by AMH. Clinical case: A 49-year-old female was referred to the Endocrinology clinic for possible having pheochromocytoma with prolonged hypertension. The patient had hypertension for 10-15 years which she is currently on metoprolol, losartan, clonidine, hydrochlorothiazide, and amlodipine for her home regimen. She also complained of having episodic hypertension which was associated with headaches, diaphoresis, palpitations, and chest pain for several years. Her blood pressure has been ranging from 100-160 over 60 -115 mmHg even though she is compliant to the medications. Also, she once was admitted to the hospital because of hypotension and needed to be taking care of in the intensive care unit. Her past medical history was significant for diabetes mellitus type 2 and anxiety. On physical examination, she had elevated blood pressure of 170/115 mmHg. The patient had no enlarged thyroid, no cushingoid appearance and denied using steroid supplements. Initial workup revealed elevated normetanephrines level in 24-hr urine and serum (1070 mcg/g; n 85-514 mcg/g and 477 pg/mL; n <148 pg/mL). In contrast with metanephrines in 24-hr urine and serum which were in normal range (154 mcg/g; n 33-192 mcg/g and <25 pg/mL; n <57 pg/mL). Serum aldosterone and cortisol level were within normal limit. An abdominal CT scan with contrast showed a 15 mm. mass was noted in the left adrenal gland with a density of -22 HU in the non-contrast image, 27 HU in portal venous phase, and 15 HU in the delay images. Pheochromocytoma was suggested at that time. The patient underwent a left adrenalectomy and pathology report revealed adrenal medullary hyperplasia. Postoperatively, her blood pressure is in the normal range, and she is able to discontinue taking all the anti-hypertensive medication. Discussion: AMH is a rare and frequently unrecognized disorder that causes hypertension. The etiology of AMH remains unknown and still unclear in etiology along with pathogenesis. Currently, there is no standard evaluation and treatment guideline for this condition. Researchers still debate that it may be a precursor lesion of pheochromocytoma since their presentation can be similar. Histopathology is still a definite diagnosis to determine the difference between both these conditions. References: 1.Young JWF, Calhoun DA, Lenders JWM, Stowasser M, Textor SC. Screening for Endocrine Hypertension: An Endocrine Society Scientific Statement. Endocrine Reviews. 2017;38(2):103-22.