A 60-year-old woman presented to the emergency department with chest palpitations that had worsened over the course of the previous 6 months. Cardiac evaluation revealed abnormal stress test findings, leading to the diagnoses of unstable angina, coronary artery disease, hypertension, and hyperlipidemia. Cardiac catheterization with angioplasty was performed, and a left anterior descending stent was placed 4 days later. The patient returned to the emergency department 4 days after stent placement describing increasing palpitations accompanied by heaviness in her chest, which lasted from 2 to 20 minutes. She was admitted to the hospital.
Before her initial visit to the emergency department, the patient had severe episodic hypertension accompanied by heaviness in her chest, palpations, sweating, flushing, shortness of breath, and tinnitus. The patient had a medical history of neurofibromatosis that was diagnosed early in her life, hyperlipidemia, uncontrolled hypertension, coronary artery disease, and acute myocardial infarction in 2010 (3 years before current hospital admission). Her medications before admission were as follows: aspirin (81 mg), ranolazine (500 mg), simvastatin (20 mg), prasugrel (10 mg), carvedilol (25 mg), omeprazole (20 mg), vitamin B12 (500 µg), and nitroglycerin (0.4 mg). The patient had a surgical history of hysterectomy, cholecystectomy, and tubal ligation. In addition, a second cardiac catheterization was performed the day of hospital admission to assess the patency of the newly placed stent. On admission, her vital signs were as follows: heart rate, 84/min; blood pressure, 128/82 mm Hg; respirations, 16/min; and oxygen saturation, 97% while breathing room air.
Initial laboratory test results revealed an elevated white blood cell count of 12,000/µL (reference range, 4500-11,000/µL), an elevated serum chloride level of 112 mmol/L (reference range, 96-106 mmol/L), an elevated glucose level of 132 mg/dL (reference range, 70-110 mg/dL), and troponin levels within reference range. The patient’s lactate level was also elevated at 2.6 mmol/L (reference range, 0.6-1.7 mmol/L). Previous research
3 has shown that high lactate levels in patients who present with symptoms similar to our patient may be associated with underlying pheochromocytomas. All other laboratory values were within reference range. An electrocardiogram showed nonspecific anterolateral ST-T changes. Findings on myocardial perfusion imaging with regadenoson showed perfusion defects in the anterior and lateral walls, and subsequent cardiac catheterization revealed patency of the recently placed stent and no new lesions.
Three days after admission, the patient was transferred to the critical care unit because of severe hypertension associated with chest pain, palpitations, sweating, flushing, shortness of breath, and tinnitus. Vital signs at the time of critical care unit admission were as follows: heart rate, 108/min; blood pressure, 224/150 mm Hg; respirations, 20/min; oxygen saturation, 98% while breathing room air; and temperature, 97.5°F. During the hospital stay, the patient continued aspirin, ranolazine, omeprazole, prasugrel, and carvedilol therapy; other medications were clonidine (0.1 mg), hydralazine (50 mg), atorvastatin (40 mg), lisinopril (20 mg), ondansetron (4 mg), and hydrocodone bitartrate/ acetaminophen (5/162.5 mg). Sodium nitroprusside treatment was also initiated, and clonidine was discontinued when she was admitted to the critical care unit for monitoring due to her hypertensive urgency. A workup to rule out pheochromocytoma was started. Results of a serum-free metanephrine and plasma catecholamine panel showed an elevated level of substantial increase in normetanephrine, plasma free at 6.0 nmol/L (reference, <0.9 nmol/L) and metanephrine, plasma free at 5.8 nmol/L (reference, <0.50 nmol/L). Catecholamine panel findings showed an elevation in plasma dopamine at 93 pg/ mL (reference range, 0-20 pg/mL), epinephrine at 1714 pg/mL (reference range, 10-200 pg/mL), and norepinephrine at 4035 pg/mL (reference range, 80-520 pg/mL). A 24-hour urine of vanillylmandelic acid was also elevated at 22.2 mg/24 h (reference range, 0.2-7.7 mg/24 h).
Abdominal computed tomography (CT) findings revealed bilateral adrenal masses (
Figure). The largest right adrenal mass measured 3.1 cm at its largest diameter and 54 Hounsfield units (HU) on a precontrast CT scan. After contrast administration, the lesion measured 70 HU, and after a 10-minute delay, the lesion measured 57 HU. The largest left adrenal mass measured 3.0 cm and 46 HU on a precontrast CT scan. Immediately after contrast administration, the mass measured 87 HU, and after a 10-minute delay, the mass measured 58 HU.
The presence of the bilateral adrenal masses and laboratory data indicating an elevation in catecholamines prompted an iodine 123 (
123I) metaiodobenzylguanidine (mIBG) study for localization of pheochromocytomas. The literature has reported the 22-hour mIBG scan to have a sensitivity of 1.00 and a specificity of 0.95, as well as a positive predictive value of 0.95 and a negative predictive value of 1.00.
4 Before the study, the patient was given a 0.15-mL oral solution of potassium iodine. Whole-body CT scans were obtained at 4 and 24 hours after the patient received the 4.8-mCi
123I mIBG injection. The results showed focal abnormal radiotracer uptake in regions corresponding to the left and right adrenal glands, which in correlation with previous CT findings were consistent with the diagnosis of bilateral pheochromocytoma. The patient’s blood pressure was optimized, and she underwent a successful bilateral adrenalectomy She continues to follow up with her primary care physician and has yet to report any recurrent or new related symptoms.