Approach Considerations
The Endocrine Society, the American Association for Clinical Chemistry, and the European Society of Endocrinology have released clinical practice guidelines for the diagnosis and management of pheochromocytoma and paraganglioma (jointly referred to as PPGL). [26, 27, 27] :
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Preoperative blockade of hormonally functional PPGL to prevent cardiovascular complications is recommended, along with preoperative medical treatment to normalize blood pressure and heart rate and a high-sodium diet with fluid intake to prevent severe hypotension after removal of the tumor.
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Blood pressure, heart rate, and glucose levels should be monitored immediately after surgery.
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Minimally invasive (eg, laparoscopic) adrenalectomy should be performed for most adrenal pheochromocytomas, with open resection reserved for very large or invasive pheochromocytomas; open resection is suggested for paragangliomas, but laparoscopic resection is an option for smaller tumors; partial adrenalectomy is also an option for certain patients.
Surgical resection of the tumor is the treatment of choice for pheochromocytoma and usually results in cure of the hypertension. Careful preoperative management is required to control blood pressure, correct fluid volume, and prevent intraoperative hypertensive crises. [47] A study by Kwon et al indicated that independent risk factors for a hypertensive attack during adrenalectomy for pheochromocytoma include a large tumor size and preoperative elevation of the urinary epinephrine level. [48]
Although there is no consensus regarding the preferred drugs for preoperative blood pressure control, alpha blockers, beta blockers, calcium channel blockers, and angiotensin receptor blockers have all been used. [49] Start alpha blockade with phenoxybenzamine 10-14 days preoperatively to allow for expansion of blood volume. The patient should undergo volume expansion with isotonic sodium chloride solution. Encourage liberal salt intake.
Initiate a beta blocker only after adequate alpha blockade (usually, 2 days). If beta blockade is started prematurely, unopposed alpha stimulation could precipitate a hypertensive crisis. Administer the last doses of oral alpha and beta blockers on the morning of surgery.
No distinction is found in hypertensive episodes during surgery for pheochromocytoma associated with multiple endocrine neoplasia type 2 (MEN 2) and non-MEN–associated pheochromocytoma. Therefore, pretreatment using alpha and beta-adrenergic blockers remains a standard of care in both groups of patients. [50]
Test plasma free metanephrines 2 weeks postoperatively. If results are within the reference range, resection is deemed complete; in such cases, patient survival approaches age-matched controls. In addition, ensure resolution of the hypertension and any associated complications.
For surgical follow-up, obtain plasma metanephrine levels yearly for 10 years. Ensure that blood pressure is under control. In patients with an underlying genetic mutation, lifelong follow-up is mandatory.
Laparoscopic Adrenalectomy
Surgical mortality rates are less than 2-3% when the operation is performed by a surgeon and an anesthesiologist who are experienced.
Use an arterial line, cardiac monitor, and Swan-Ganz catheter. Administer stress-dose steroids if bilateral resection is planned.
An anterior midline abdominal approach was used in the past; in current practice, however, laparoscopic adrenalectomy is the preferred procedure for lesions smaller than 8 cm. If the pheochromocytoma is intra-adrenal, the standard approach is to remove the entire adrenal gland. In the case of a malignant pheochromocytoma, resect as much of the tumor as possible. [3, 51, 52]
A study by Scholten et al found that unilateral subtotal adrenalectomy is a feasible strategy in patients with MEN2 who have pheochromocytoma. It has comparable recurrence rates and less complications of steroid replacement compared with unilateral total adrenalectomy. [53]
In a study by Paraby et al, severe hypertension (systolic blood pressure >200 mm Hg) was associated with 5 of 35 pheochromocytoma resections (14.3%), compared with 2 of 106 nonpheochromocytoma adrenal tumor resections (1.9%). [3] However, no patient in either group had transient or persistent systolic blood pressure of greater than 220 mm Hg. There were no significant differences in recovery room hemodynamic parameters, frequency of persistent hypotension, or occurrence of heart rates greater than 120/min between the 2 groups.
Pheochromocytoma in Pregnancy
If pheochromocytoma is found during pregnancy, initiate alpha-adrenergic blockade (with phenoxybenzamine) as soon as the diagnosis is confirmed. Remove the tumor by laparoscopic adrenalectomy as soon as possible during the first 2 trimesters, after proper preparation. Pregnancy need not be terminated. Spontaneous abortion is very likely, however.
During the third trimester, the patient should be managed medically until fetal lung maturity is confirmed. Cesarean delivery is preferred, as mortality may be higher with vaginal delivery. The tumor may be removed during the same session as the cesarean section, or it can be removed post partum. [24]
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Axial, T2-weighted magnetic resonance imaging (MRI) scan showing large left suprarenal mass of high signal intensity on a T2-weighted image. The mass is a pheochromocytoma.
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Abdominal computed tomography (CT) scan demonstrating left suprarenal mass of soft-tissue attenuation representing a paraganglioma.
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Adrenalectomy specimen containing pheochromocytoma. Non-neoplastic adrenal cortex (yellow) surrounds a small tan-red tumor in the medullary region, representing a pheochromocytoma.
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H and E, high power, showing classic "balls of cells" feature of a pheochromocytoma. Endocrine tumors such as a pheochromocytoma typically show some degree of nuclear pleomorphism ("endocrine atypia") which does not indicate malignancy.
