AN UNUSUAL CASE OF HYPERTENSION. S. Kripalani 1 ; Emory University, Atlanta, GA LEARNING OBJECTIVES: 1) Explore causes of secondary hypertension in a young man. 2) Recognize the appearance and pathophysiology of Page kidney. CASE INFORMATION: A 27 year-old narcotics agent presented for evaluation of previously untreated high blood pressure. Manual readings over the past year ranged from 140 ± 151/96 ± 110. He complained of daily bifrontal headaches, as well as occasional palpitations and diaphoresis, but only when working in high-stress situations. Review of systems was otherwise negative, as were past medical history and medication use, including OTC products. He denied smoking and illicit drug use, but he used chewing tobacco and had 2 ± 3 alcoholic drinks per week. He used to play high school football and had been in a car accident years ago, with no apparent injury. His father received a heart transplant for idiopathic cardiomyopathy. Family history was otherwise negative. Blood pressure was 162/108 in the left arm, 152/104 in the right arm, and 154/106 in the right leg. Heart rate was 64, height 71 inches, and weight 196 pounds. He appeared comfortable and well-developed. Physical examination was unremarkable. EKG, chest x-ray, blood count, basic chemistry panel, TSH, urinalysis, and drug screen were normal. The patient was started on amlodipine, to avoid interfering with anticipated testing, and his blood pressure responded appropriately. Initial 24-hour urine catecholamines were elevated, prompting a CT scan to help localize a potential pheochromocytoma. The CT showed normal adrenals, but unexpectedly, the left kidney had a 5x5x11cm subcapsular fluid collection, known as Page kidney. An MRI/MRA confirmed the CT findings and demonstrated normal vasculature. Renin levels were slightly elevated Ð supine 1.7 ng/mL/hr (0.2 ± 1.6) and upright 4.9 ng/mL/hr (0.5 ± 3.3) . Cortisol, aldosterone, and upright aldosterone/renin ratio were within normal limits. Head CT and repeat urine studies were normal. Given the imaging results, the initial catecholamine elevation was deemed a false positive. DISCUSSION: Potential causes of secondary hypertension included renal parenchymal and renovascular diseases, coarctation of the aorta, mineralocorticoid excess (either through hyperaldosteronism or use of chewing tobacco or licorice), renin-producing tumors, pheochromocytoma, Cushing's syndrome, congenital adrenal hyperplasia, substance abuse, exogenous hormones or sympathomimetics, sleep apnea, hypo-and hyperthyroidism, hyperparathyroidism, acromegaly, carcinoid, and increased intracranial pressure. Page kidney is rare cause of hypertension resulting from compression of the renal parenchyma. High blood pressure is mediated by elevated renin levels, which are thought to be secondary to local ischemia or parenchymal scarring. In the model which he described in 1939, Page used cellophane wrapping to constrict the kidneys. However, most cases in clinical practice are due to a subcapsular hematoma resulting from blunt trauma, usually associated with contact sports or an accident. If blood pressure cannot be controlled medically, percutaneous drainage or nephrectomy can be curative.