Endocrine Abstracts

Introduction: Pheochromocytoma is a rare tumor of chromaffin cells localized in the adrenal gland. It is responsible of secretion of catecholamines in a supra physiologic amount, leading to hypertension. Some patients may present with hypotension despite having high circulating levels of catecholamines. The challenge is to stabilize blood pressure by medication in cases with fluctuation of blood pressure.

Case presentation: 49-year-old woman suffered from recurrent right hypochondrium pain and paroxystic headache, palpitations and sweats. She has no history of hypertension and no family history of pheochromocytoma. Urinary 24-h excretion levels of epinephrine, norepinephrine, and dopamine, were highly increased. Abdominal CT Scan showed a right adrenal mass measuring 71×86 cm, discreetly enhanced after injection of PDC and with areas of cystitis and necrosis. After being hospitalized, monitoring of blood pressure and heart rate showed an extreme fluctuation with systolic pressure peaks reaching 210 mmHg and systolic pressure nadir reaching 70 mmHg; and the HR fluctuates from 65 to 120 beats/min. Doxazosin was orally administrated starting by a dose of 1 mg/day, then 2 mg/day, 10 days before surgery. However, the patient kept the fluctuations until day 6 of treatment. Intravenous fluids were introduced 3 days before surgery. Right adrenalectomy was performed through laparotomy with two incidental high BP episodes during surgery. Histological examination confirmed the Pheochromocytoma. BP and HR remain stable after adrenalectomy.

Discussion: Hypotension and BP fluctuation are rare phenomena in patients with pheochromocytoma. The mechanisms by which hypotension and BP fluctuation occur in these patients despite an increase in catecholamine level remain unclear. There is no consensus concerning management of hypotension and BP fluctuation. The Endocrine Society recommend a preoperative blockade (by α-adrenergic receptor blockers as the first choice) for all patients with hormonally functional pheochromocytoma despite the BP status. Some studies showed a beneficial effect of treatment with a combination of intravenous norepinephrine and doxazosin on BP fluctuation. Adrenalectomy should be performed after stabilization of BP.

Conclusion: We presented a case of Pheochromocytoma in a patient who had an important BP and HR fluctuations. The preoperative preparation must be delicate with a close monitoring of BP.

References: Pesek. J. et al. Unusual case of pheochromocytoma with a surprising response to the intravenous administration of norepinephrine. Circulation. 2005. Streeten. D.H. et al. Mechanisms of orthostatic hypotension and tachycardia in patients with pheochromocytoma. Am J Hypertens. 1996.Jacques. W.M. et al. Pheochromocytoma and Paraganglioma: An Endocrine Society Clinical Practice Guideline. JCEM June 2014.